In order to track subscriptions, it is necessary to parse the receipt you receive from the app store. You can do this at purchase time and store that data (Unity IAP does not have any inventory management features) and then again at app start to check the status of the subscription.There are some more details in this forum thread: https://forum.unity3d.com/threads/how-do-i-track-auto-renewing-subscriptions.476293/