How to restore purchase iOS
As long as you are using the same Apple ID, you should be able to get your subscription back. Simply go to AppBlock > More > Restore purchase. After tapping on that AppBlock should recognise your premium.
If you have any troubles with these steps, head to the premium buying page and below the “Other options” button tap the Restore purchases.
If that doesn’t help, please follow the steps in the following guide: https://support.apple.com/en-us/HT204530 .