When the tutorial has been completed, you will be asked if you would like to Link your account with Facebook. You can either Link now, or hit the X at the top of the message prompt. 
If you decide later that you would like to Link your Guest game with Facebook, you can do so from the in-game Options Menu under Settings tab (Mail Icon). When you select the “Link To Facebook” button, you will be asked if you would like to “Link” your game with Facebook. Please note that if your current Facebook is already Linked to another account, you will be suggested to login via the Main Menu.
If you want to link your Guest account with Facebook although you already created a Facebook game, we would have to delete your Facebook game. This way your Facebook account will be free to link your Guest game to it. In this case, please contact us with your request and the support key of the Facebook game to be deleted.