Subscriptions on App Store are for an indefinite term, and you’ll be charged at the beginning of each billing cycle according to your subscription terms (for example, weekly, annually or another period), unless you unsubscribe.
How to cancel a subscription on your iPhone or iPad
Open the Settings app.
Tap your name.
Tap Subscriptions.
Tap the subscription.
Tap Cancel Subscription. You may need to scroll down to find the Cancel Subscription button. If there is no Cancel button or you see an expiration message in red text, the subscription has already been cancelled.