Hi @Pensive_Introvert! The AG Auth has been intended for hobby/proof of concept use, so that you can create and manage a small amount of users from Composer and log them in using the provided flow functions. There has not been an AppGyver provided authentication method for production use with user registration and password change flow functions, and that does not change with this initial Firebase auth implementation.
However, you can do the Firebase signup/password change as you would have before via HTTP requests. Firebase auth integration has been discussed for example in this thread.