You can only play your game on multiple devices if you have a Facebook account connected or over devices using the same Apple ID.
To access your game on another device, just ensure you are logged into your Facebook account on the Facebook app and web browser and choose “log in” and “facebook” from the main menu!
When playing across more than one device always make sure that when finishing a play session on one device you wait at least 20 seconds between the last action and closing the game. When you close the game, please ensure it is fully force quit before opening your game on another device.