

You’re kind of asking the wrong question.
Are there ways to share stuff with a group of people that are self-hosted? Absolutely.
Can you get security through those means? Not without some unified authentication.
Maybe back up a few steps and figure out specifically how much trouble you’re willing to go through for this. There’s a reason these photo sharing platforms exist with sharing and permissions.
Then just start an Immich instance and share them that way. Easiest route if you want to make them browsable first.