Maybe NIP98 could be a way to do it.
Discussion
It is a way, just not simple in php. Next on my priority list 🐶🐾🫡
This is how we did it with the user galleries at nostrcheck, nostr:npub137c5pd8gmhhe0njtsgwjgunc5xjr2vmzvglkgqs5sjeh972gqqxqjak37w I'm here for whatever you need 🙂
I gotta find time for that, and it’s a rare commodity for me. PHP doesn’t have good libs, so I have to rely on nginx and njs module to write that layer and pass npub to the PHP fcgi. I wish the whole thing was written in TS, then it would have been done yesterday. I have the skeleton written some time ago: https://github.com/nostrbuild/nostr.build/blob/main/libs/NostrAuthHandler.class.php
🐶🐾🫡🫂💜