Subcap is not authorized to do anything about the subscriptions.
To change the subscription plan:
For iOS: Go to your phone’s homepage, go to Settings> Your Apple ID> Subscriptions and you will see Subcap in the list, click it. You can see all the subscription plans from there and select one of them.
For Android: Open the Google Play app, tap the profile icon at the top right, tap “Payments & subscriptions” and then Subscriptions. Select Subcap>Manage>Update