To turn off notifications on Apple devices, go to Settings > Notifications, and select the apps you'd like to modify notifications for. For more information on Apple device notifications, please visit https://support.apple.com/en-us/HT201925

If you would like to modify notifications on your Android device, open your game, go into your settings, and disable notifications.  Once you've done this, you'll have to go a step further and disable notifications through your phone settings, as documented here: http://www.howtogeek.com/204187/how-to-disable-app-notifications-in-android/

If you would like to change your Facebook game settings, follow the instructions on this video: https://www.youtube.com/watch?v=HVyjS_Ypl74