When you launch Book of Life: Sugar Smash for the first time, the game will ask you for your age. If you put an age that doesn't meet our guidelines, you won't be able to connect to Facebook.
If you accidentally put in the wrong age and would like to connect to Facebook, you'll have to uninstall and re-install your game and select your age again. Please note that in doing so, you may lose the progress you've made on the game.
If you're still having trouble, please submit a support ticket in the game, by tapping the "gear" icon on the map screen, and then "support," or you can open an online support ticket here.