As the question, for Login with google in firebase need to set google-service but if you create new react-native project with create-react-native-app there will have no "android" or "ios" folder (accept used "eject") so, anyone have a suggestion for me? However I've no idea for how to setting google-service in my project too (even I "eject" the project).
It isn't necessary to make any changes to the android or ios folders in order to support Google sign in with firebase on an app built with Expo.