Thank you for the feedback and I will look more into it!
I know that it is not too clear, but I think I said in the text next to the UI that the password can be a new one.
Currently, as I said, I am using Google's firebase, as such it has OAuth for google accounts. The database currently doesn't contain passwords - only email and UID. The game creates an automatic Auth file on your computer, which is encrypted and auto read upon opening the game if it exists.
I will look into how Patreon does this and I think there was a way, when I was researching their API. As the game is still in a demo, the current system is made to just work. In the official release, it probably won't even require Patreon emails too and would verify your Patreon tier through OAuth seperately but not use it to log in.
Anyways, thank you for the feedback and I will be more careful with the security going forward!