1.On the Home screen, tap Settings.
2. Tap App and iTunes Stores.
3. Tap your Apple ID.
4. Tap View Apple ID. You might need to sign in.
5. Under Subscriptions, tap Manage.
6. Tap the subscription that you want to manage.

Use the options to manage your subscription. You can choose a different subscription period, or turn off Automatic Renewal. Turn off Automatic Renewal to cancel a subscription. Your subscription will stop at the end of the current billing cycle.

Important: Uninstalling an app will not automatically stop your subscription. You must cancel it first to end your subscription. If you uninstall the app without canceling your subscription, you will still be charged.

Canceling a subscription will not retroactively refund payments, and previously charged subscription fees cannot be pro-rated based on cancellation date. 

 If you cancel an existing subscription and decide to subscribe again later, you will be charged the most recent price.

 For more info, please go to https://support.apple.com/en-us/HT202039