I am working on a project in Android Studio. I was following a tutorial for Facebook Login for Android (<https://developers.facebook.com/docs/facebook-login/android>).

And To add the Facebook Login button, first, it had to be added in layout XML file with the full class name, `com.facebook.widget.LoginButton`. But I can't find it anywhere. I even tried with Double shift shortcut, still no success.

Am I doing something wrong? If yes, please guide me in right direction or if there is another alternative approach to add facebook login button. 

Thanks.