You should still use the Main Server. Here is the Main server sources.list contents:
Summary
# deb cdrom:[Zorin-OS 16 Core 64bit]/ focal main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu focal main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu focal-updates main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu focal universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal universe
deb http://archive.ubuntu.com/ubuntu focal-updates universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu focal multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal multiverse
deb http://archive.ubuntu.com/ubuntu focal-updates multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu focal partner
# deb-src http://archive.canonical.com/ubuntu focal partner
deb http://archive.ubuntu.com/ubuntu focal-security main restricted
# deb-src http://security.ubuntu.com/ubuntu focal-security main restricted
deb http://archive.ubuntu.com/ubuntu focal-security universe
# deb-src http://security.ubuntu.com/ubuntu focal-security universe
deb http://archive.ubuntu.com/ubuntu focal-security multiverse
# deb-src http://security.ubuntu.com/ubuntu focal-security multiverse
# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.
# deb cdrom:[Zorin-OS 16 Core 64bit]/ focal main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu focal main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu focal-updates main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu focal universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal universe
deb http://archive.ubuntu.com/ubuntu focal-updates universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu focal multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal multiverse
deb http://archive.ubuntu.com/ubuntu focal-updates multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu focal partner
# deb-src http://archive.canonical.com/ubuntu focal partner
deb http://archive.ubuntu.com/ubuntu focal-security main restricted
# deb-src http://security.ubuntu.com/ubuntu focal-security main restricted
deb http://archive.ubuntu.com/ubuntu focal-security universe
# deb-src http://security.ubuntu.com/ubuntu focal-security universe
deb http://archive.ubuntu.com/ubuntu focal-security multiverse
# deb-src http://security.ubuntu.com/ubuntu focal-security multiverse
# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.
sudo apt update
Get:1 Index of /ubuntu focal InRelease [265 kB]
Get:2 https://cli.github.com/packages stable InRelease [3 917 B]
Get:3 Index of /ubuntu focal-updates InRelease [114 kB]
Get:4 Index of /ubuntu focal-backports InRelease [108 kB]
Get:5 Index of /ubuntu focal-security InRelease [114 kB]
Err:2 https://cli.github.com/packages stable InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23F3D4EA75716059
Get:6 Index of /ubuntu focal/main amd64 Packages [970 kB]
Get:7 Index of /ubuntu focal/main i386 Packages [718 kB]
Get:8 Index of /ubuntu focal/main Translation-en [506 kB]
Get:9 Index of /ubuntu focal/main amd64 DEP-11 Metadata [494 kB]
Get:10 Index of /ubuntu focal/main DEP-11 48x48 Icons [98,4 kB]
Get:11 Index of /ubuntu focal/main DEP-11 64x64 Icons [163 kB]
Get:12 Index of /ubuntu focal/main DEP-11 64x64@2 Icons [15,8 kB]
Get:13 Index of /ubuntu focal/main amd64 c-n-f Metadata [29,5 kB]
Get:14 Index of /ubuntu focal/restricted amd64 Packages [22,0 kB]
Get:15 Index of /ubuntu focal/restricted i386 Packages [8 112 B]
Get:16 Index of /ubuntu focal/restricted Translation-en [6 212 B]
Get:17 Index of /ubuntu focal/restricted amd64 c-n-f Metadata [392 B]
Get:18 Index of /ubuntu focal/universe i386 Packages [4 642 kB]
Get:19 Index of /ubuntu focal/universe amd64 Packages [8 628 kB]
Get:20 Index of /ubuntu focal/universe Translation-en [5 124 kB]
Get:21 Index of /ubuntu focal/universe amd64 DEP-11 Metadata [3 603 kB]
Get:22 Index of /ubuntu focal/universe DEP-11 48x48 Icons [3 016 kB]
Get:23 Index of /ubuntu focal/universe DEP-11 64x64 Icons [7 794 kB]
Get:24 Index of /ubuntu focal/universe DEP-11 64x64@2 Icons [44,3 kB]
Get:25 Index of /ubuntu focal/universe amd64 c-n-f Metadata [265 kB]
Get:26 Index of /ubuntu focal/multiverse i386 Packages [74,7 kB]
Get:27 Index of /ubuntu focal/multiverse amd64 Packages [144 kB]
Get:28 Index of /ubuntu focal/multiverse Translation-en [104 kB]
Get:29 Index of /ubuntu focal/multiverse amd64 DEP-11 Metadata [48,4 kB]
Get:30 Index of /ubuntu focal/multiverse DEP-11 48x48 Icons [23,1 kB]
Get:31 Index of /ubuntu focal/multiverse DEP-11 64x64 Icons [192 kB]
Get:32 Index of /ubuntu focal/multiverse DEP-11 64x64@2 Icons [214 B]
Get:33 Index of /ubuntu focal/multiverse amd64 c-n-f Metadata [9 136 B]
Get:34 Index of /ubuntu focal-updates/main amd64 Packages [2 397 kB]
Get:35 Index of /ubuntu focal-updates/main i386 Packages [788 kB]
Get:36 Index of /ubuntu focal-updates/main Translation-en [409 kB]
Get:37 Index of /ubuntu focal-updates/main amd64 DEP-11 Metadata [275 kB]
Get:38 Index of /ubuntu focal-updates/main DEP-11 48x48 Icons [60,8 kB]
Get:39 Index of /ubuntu focal-updates/main DEP-11 64x64 Icons [98,3 kB]
Get:40 Index of /ubuntu focal-updates/main DEP-11 64x64@2 Icons [29 B]
Get:41 Index of /ubuntu focal-updates/main amd64 c-n-f Metadata [16,3 kB]
Get:42 Index of /ubuntu focal-updates/restricted amd64 Packages [1 610 kB]
Get:43 Index of /ubuntu focal-updates/restricted i386 Packages [30,4 kB]
Get:44 Index of /ubuntu focal-updates/restricted Translation-en [227 kB]
Get:45 Index of /ubuntu focal-updates/restricted amd64 c-n-f Metadata [620 B]
Get:46 Index of /ubuntu focal-updates/universe i386 Packages [711 kB]
Get:47 Index of /ubuntu focal-updates/universe amd64 Packages [1 026 kB]
Get:48 Index of /ubuntu focal-updates/universe Translation-en [239 kB]
Get:49 Index of /ubuntu focal-updates/universe amd64 DEP-11 Metadata [408 kB]
Get:50 Index of /ubuntu focal-updates/universe DEP-11 48x48 Icons [274 kB]
Get:51 Index of /ubuntu focal-updates/universe DEP-11 64x64 Icons [488 kB]
Get:52 Index of /ubuntu focal-updates/universe DEP-11 64x64@2 Icons [29 B]
Get:53 Index of /ubuntu focal-updates/universe amd64 c-n-f Metadata [23,6 kB]
Get:54 Index of /ubuntu focal-updates/multiverse amd64 Packages [25,2 kB]
Get:55 Index of /ubuntu focal-updates/multiverse i386 Packages [8 440 B]
Get:56 Index of /ubuntu focal-updates/multiverse Translation-en [7 408 B]
Get:57 Index of /ubuntu focal-updates/multiverse amd64 DEP-11 Metadata [944 B]
Get:58 Index of /ubuntu focal-updates/multiverse DEP-11 48x48 Icons [1 867 B]
Get:59 Index of /ubuntu focal-updates/multiverse DEP-11 64x64 Icons [2 497 B]
Get:60 Index of /ubuntu focal-updates/multiverse DEP-11 64x64@2 Icons [29 B]
Get:61 Index of /ubuntu focal-updates/multiverse amd64 c-n-f Metadata [604 B]
Get:62 Index of /ubuntu focal-backports/main i386 Packages [36,1 kB]
Get:63 Index of /ubuntu focal-backports/main amd64 Packages [45,7 kB]
Get:64 Index of /ubuntu focal-backports/main Translation-en [16,3 kB]
Get:65 Index of /ubuntu focal-backports/main amd64 DEP-11 Metadata [8 000 B]
Get:66 Index of /ubuntu focal-backports/main DEP-11 48x48 Icons [6 984 B]
Get:67 Index of /ubuntu focal-backports/main DEP-11 64x64 Icons [10,5 kB]
Get:68 Index of /ubuntu focal-backports/main DEP-11 64x64@2 Icons [29 B]
Get:69 Index of /ubuntu focal-backports/main amd64 c-n-f Metadata [1 420 B]
Get:70 Index of /ubuntu focal-backports/restricted amd64 c-n-f Metadata [116 B]
Get:71 Index of /ubuntu focal-backports/universe amd64 Packages [24,9 kB]
Get:72 Index of /ubuntu focal-backports/universe i386 Packages [13,8 kB]
Get:73 Index of /ubuntu focal-backports/universe Translation-en [16,3 kB]
Get:74 Index of /ubuntu focal-backports/universe amd64 DEP-11 Metadata [30,5 kB]
Get:75 Index of /ubuntu focal-backports/universe DEP-11 48x48 Icons [13,2 kB]
Get:76 Index of /ubuntu focal-backports/universe DEP-11 64x64 Icons [22,6 kB]
Get:77 Index of /ubuntu focal-backports/universe DEP-11 64x64@2 Icons [29 B]
Get:78 Index of /ubuntu focal-backports/universe amd64 c-n-f Metadata [880 B]
Get:79 Index of /ubuntu focal-backports/multiverse amd64 c-n-f Metadata [116 B]
Get:80 Index of /ubuntu focal-security/main amd64 Packages [2 007 kB]
Get:81 Index of /ubuntu focal-security/main i386 Packages [559 kB]
Get:82 Index of /ubuntu focal-security/main Translation-en [327 kB]
Get:83 Index of /ubuntu focal-security/main amd64 DEP-11 Metadata [60,0 kB]
Get:84 Index of /ubuntu focal-security/main DEP-11 48x48 Icons [18,9 kB]
Get:85 Index of /ubuntu focal-security/main DEP-11 64x64 Icons [36,0 kB]
Get:86 Index of /ubuntu focal-security/main DEP-11 64x64@2 Icons [29 B]
Get:87 Index of /ubuntu focal-security/main amd64 c-n-f Metadata [12,2 kB]
Get:88 Index of /ubuntu focal-security/restricted i386 Packages [29,1 kB]
Get:89 Index of /ubuntu focal-security/restricted amd64 Packages [1 508 kB]
Get:90 Index of /ubuntu focal-security/restricted Translation-en [213 kB]
Get:91 Index of /ubuntu focal-security/restricted amd64 c-n-f Metadata [624 B]
Get:92 Index of /ubuntu focal-security/universe i386 Packages [581 kB]
Get:93 Index of /ubuntu focal-security/universe amd64 Packages [797 kB]
Get:94 Index of /ubuntu focal-security/universe Translation-en [156 kB]
Get:95 Index of /ubuntu focal-security/universe amd64 DEP-11 Metadata [94,4 kB]
Get:96 Index of /ubuntu focal-security/universe DEP-11 48x48 Icons [45,5 kB]
Get:97 Index of /ubuntu focal-security/universe DEP-11 64x64 Icons [94,9 kB]
Get:98 Index of /ubuntu focal-security/universe DEP-11 64x64@2 Icons [29 B]
Get:99 Index of /ubuntu focal-security/universe amd64 c-n-f Metadata [17,0 kB]
Get:100 Index of /ubuntu focal-security/multiverse amd64 Packages [22,9 kB]
Get:101 Index of /ubuntu focal-security/multiverse i386 Packages [7 184 B]
Get:102 Index of /ubuntu focal-security/multiverse Translation-en [5 488 B]
Get:103 Index of /ubuntu focal-security/multiverse amd64 DEP-11 Metadata [940 B]
Get:104 Index of /ubuntu focal-security/multiverse DEP-11 48x48 Icons [1 867 B]
Get:105 Index of /ubuntu focal-security/multiverse DEP-11 64x64 Icons [2 497 B]
Get:106 Index of /ubuntu focal-security/multiverse DEP-11 64x64@2 Icons [29 B]
Get:107 Index of /ubuntu focal-security/multiverse amd64 c-n-f Metadata [528 B]
Reading package lists... Done
W: GPG error: https://cli.github.com/packages stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23F3D4EA75716059
E: The repository 'https://cli.github.com/packages stable InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
When i run sudo apt upgrade:
sudo apt upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
Get more security updates through Ubuntu Pro with 'esm-apps' enabled:
rpm2cpio libmaven3-core-java libgegl-0.4-0 ant python2.7-minimal
libmagickwand-6.q16-6 libgegl-common python2.7 librpmio8 rpm-common librpm8
libhttpclient-java libopenexr24 libsdl2-2.0-0 libsdl2-2.0-0
libmagickcore-6.q16-6 libpython2.7-minimal libpython2.7-stdlib ant-optional
imagemagick-6-common
Learn more about Ubuntu Pro at Ubuntu Pro | Ubuntu
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. ?
Open "Software and Updates" and on the Other Software section, remove cli.github.com (or everything that says "Github". Then click on reload, and repost the output of sudo apt update