If you want all your data to be removed automatically, you may do so by following the next steps:
1. On Facebook access Account-> Settings & Privacy -> Settings -> Apps and Websites.
2. Find the Game you want to delete in the list of apps.
3. Press “Remove” to remove the game from your list.
4. On the pop-up window check “Allow Facebook to notify the Game that your login connection was removed.
They may offer you another way to log in.”
Please note, if you check this option all your data will be removed immediately without the possibility of recovery.
5. Press “Remove”.