How do I cancel a subscription on an app?

Change or cancel your subscriptions

1. Go to Settings > [your name] > iTunes & App Store.
2. Tap your Apple ID at the top of the screen, then tap View Apple ID. You might need to sign in with your Apple ID.
3. Scroll to Subscriptions, then tap it.
4. Tap the subscription that you want to manage. ...
5. Use the options to manage your subscription.

View, change, or cancel your subscriptions - Apple Support

https://support.apple.com/en-us/HT202039