I am guessing... on this...
But it sounds like the file is referencing your lsb_release file to check if it is a supported distro.
You might try temporarily changing your /etc/lsb-release file to read as Ubuntu 20.04, upon which Zorin OS 16 is based.
DISTRIB_ID=Zorin
DISTRIB_RELEASE=16
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Zorin OS 16.2"
To
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Zorin OS 16.2"
Once you have installed the software, revert your lsb-release file back to original.