While AUR packages generally show up on pamac, there is a specific one which does not.
https://archlinux.org/packages/community/any/gramps/
When I look for “gramps” on pamac, I only get to see the community package which is slightly outdated. I cannot figure out why the AUR package mentioned above is not listed.
As aforementioned, different AUR packages (nheko etc.) happily show up.