Most of the method from this thread wont work with newer drivers. AMD changed their driver packaging method recently.
I suggest you try to find older drivers. I have installed amdgpu-pro-20.40-1147286-ubuntu-20.04
Everything newer either will not install or will not work properly, at least on Debian. On PopOS it should be similar.
To be clear. This will give you OpenCL only, so you can forget about using Blender 3.0 and newer if you want GPU rendering.
AMD does not release PRO drivers for PopOS nor for Debian. If you want to render on GPU with Blender 3.0 and newer your best bet is to wait until ROCm is packaged in Debian, so it can finally trickle down to PopOS. When it happens - its hard to tell.
Alternatively you can compile ROCm from source, but it can be complicated.