The only way to secure your progress and make sure you never lose it is to connect your game to Google Play or Apple ID. Here's how you do it:
In the Main screen, tap on the settings icon ⚙️
In the pop-up window, tap on Account
Tap the button with the account you want to link to your game and follow the instructions
After successfully connecting your account to the game, you can be certain your progress is safe and you won't lose it if you don't have access to the current device or want to switch to a new one.