I have set sign in provider to only be Google:
providers = [FIRGoogleAuthUI()]
and yet when I launch, there is an email option in addition to google. Is the email option required?
Email provider can be disabled via flag FUIAuth.signInWithEmailHidden
Here is code example: https://github.com/firebase/FirebaseUI-iOS/blob/master/samples/objc/FirebaseUI-demo-objc/Samples/Auth/FUIAuthViewController.m#L177