There are 2 options to move your subscription to another device:
On your new device, log in to the app with the same account you used on your old device.
On the new device, go to the More tab in the bottom right corner and click Restore Purchases. It should do the trick if you're signed in with the same Apple ID you used to start the subscription.
Feel free to contact us if you have any further questions at email@example.com, and we will be happy to assist you!