When you are playing DoubleDown Casino on your computer, you are playing while logged in to Facebook. On the mobile app, you have the option to play either logged in to Facebook or as a Guest. A Guest account is completely separate from your Facebook-connected account, and there is no way to transfer or share items between them. If you tapped Play Now in the app rather than Facebook Login, you are playing as a Guest.
Learn how to switch between your Facebook and Guest accounts on your device.