As you play, the game progress is automatically stored in iCloud (assuming the iCloud account is configured correctly). When you reinstall the game and log in to iCloud again, your progress will be automatically restored.
Category: How to restore or sync my game progress?
How to restore or sync my game progress?
Have you reinstalled the game? Changed your device? Are you playing on two devices? It may happen that you need to restore or sync your game progress.