Ionic1 & Firebase V3 Login

Hey everybody,
maybe someone can help me finding a solution to a seemingly simple problem:
i want integrate a login/user system with email and password, so i choose firebase.
i get the sample from firebase to work but when i try to get them to my ionic project
i always get the “not authorized for OAuth operations” in the console - i don’t get it,
i don’t want to use any Facebook/google/etc login i want to use normal mail&password.
all stuff i could find is for firebase v2 but nothing for v3.
thx for any help :+1: