As others have said "Ya doin it wrong!"

AMD has the AMDGPU kernel driver already in place in the linux kernel, and excluding the newest generations of cards for about a month or two after they come out, that part should work fine. Additionally, you need Mesa installed for the userspace drivers. It is typically preinstalled and covers the OpenGL and Vulkan drivers for your card.

Pretty much the only time you want to run the driver from AMD's site is if you're using some particular professional applications, otherwise Mesa tends to outperform it. There are relatively few games that AMDVLK (the AMD official open source Vulkan driver) is ahead, and it's got an edge in most (all?) raytracing cases currently.

Lastly, the reason it doesn't work is because the driver install script is checking your os-release version to see if it matches the Ubuntu version it was packaged for. If you're confident that you can fix any problems that arise from doing this, you could presumably just change the string in /etc/os-release to match what it's looking for. I don't recommend doing this, though, unless you don't care if the drivers break things because they weren't packaged for the release you're using.