Firebase authentication delegate/support for firebase.
Make sure to include Firebase in your app. This does not perform any config.
Follow googles instructions. It varies depending on platform. You will need to edit HTML/Android/iOS files and set things up in the console. This tutorial doesn't really cover that.
dart_board_firebase_core dependency will handle the firebase init for you.
Just include it, and place a LoginButton();
Otherwise, standard dart_board_authentication usage for auth updates and user info.