We're aware of an issue with Facebook purchases for all King Games and our team is on it. 🛠️ Hang tight while we fix things! You can still enjoy the game, and we'll keep you posted once it's solved.
I'm sure the Friends Option will be added later since the game is only about 5 weeks old :) Also they will proppaly make the "Connect To Facebook" Option so you can see all your friends stats as well ^^'