I tried the first and got this -
mac@mac-MacBookPro:~$ sudo apt install firmware-b43-installer
[sudo] password for mac:
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package firmware-b43-installer
*** Then I tried the first part of your second line and got this
mac@mac-MacBookPro:~$ sudo apt install linux-firmware
Reading package lists... Done
Building dependency tree
Reading state information... Done
linux-firmware is already the newest version (1.173.19).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
mac@mac-MacBookPro:~$
*** If I'm right that means the correct driver is already there?
But I have no ethernet - and when I look at the options in the bottom right network connection section the ethernet bits are still greyed out.
One interesting things - when I get to the boot screen it gave me 2 options - one was zorin and one was zorin with advanced options. I have never seen those 2 options before. When Ive booted before it just booted.... so why 2? I'm going to try booting advanced and see what happens...
Its so weird as I was able to install the Broadcom drivers as part of the 2 required prop drivers before...
But as before when I search for additional drivers the Broadcon wifi ones dont come up - like they are not needed - or the hardware doesnt exist... but yet we know they are there...