The login process
for Facebook through GameMaker: Studio is quite straightforward and
requires that you have this tab set up correctly. If you are
wanting to use the Facebook functions in your game, here you should
tick the box labeled "Use Facebook" and below that supply your
App ID (also called API Key) so that GameMaker: Studio can
connect and communicate with the Facebook API. This key can be
found through the Apps tab on the Facebook Developers page,
where you should have a section that looks a bit like this:
Once you have the App Id, you
should copy it into the Facebook App Id field of the tab.
Once those two simple steps have been completed, you are ready to
use the specialist Facebook
functions that GameMaker: Studio has to communicate with
Facebook for getting information about the user and posting text
and images to their wall.
You should also add in your "Facebook App Display Name" if you are developing for the iOS target platform. This is the app "Display Name" from your app settings in >developers.facebook.com.
NOTE: This functionality is limited to the Professional Version of GameMaker: Studio.