I was making a multiplayer project with firebase, and I couldn't use snap accounts, so to play the game you need to log in with google, or make your account specially for this. Does snap support oauth, and can you add it if not?

It does not support OAuth. We might add it at some point, but it won't be very soon.

That is one thing it could be used in. The point is that data can be saved on firebase by snap user.