Getting GPU acceleration working is a common task for those of us running Plex or Jellyfin. There is not much documentation for getting the NVIDIA container stack to work with Podman, even less on Gentoo, plus there have been a lot of changes to NVIDIA's container toolkit lately.
I have been fighting with Podman for a while now and just recently got it working 1:1 with my Docker setup. Gentoo may not be the most popular or easy to use distro but I documented it in case some poor soul runs across it searching the web.
I merely cross-posted it. If you asked the OP in the original post, I'm sure they'd be happy to - I just don't feel comfortable posting it myself as it's not my own.