I can't cancel my payment

You may cancel subscription for future payment

How to see or cancel subscriptions on your iPhone, iPad, or iPod touch

1. Open the Settings app.
2. Tap your name.
3. Tap Subscriptions. (If you don't see "Subscriptions," tap "iTunes & App Store" instead. ...
4. Tap the subscription that you want to manage. Don't see the subscription that you're looking for?
5. Tap Cancel Subscription.

See or cancel your subscriptions - Apple Support

See or cancel your subscriptions - Apple Support