Android Question How to handle error event in Firebase Auth?

[hongbii]

Hi,
May i know how to handle the firebase auth error event?
For example, i have an error message and i need to pop up the message and ask user to login with google instead:

error: com.google.firebase.auth.FirebaseAuthUserCollisionException: An account already exists with the same email address but different sign-in credentials. Sign in using a provider associated with this email address.

Thank you

 

[hongbii]

Thanks but in my case I need only one account per email in the registration. and i found that the Facebook Auth return null User.Email If i do this