There are plenty of great subscription-based services available through your iPhone, but sometimes you need to cancel a subscription or face unwanted charges. Here's how to prevent auto-renewal on iPhones running iOS 14, iOS 13, iOS 12, or iOS 11.
Cancel automatic renewal of subscription on iPhone and iPad for all iOS devices
Here's how to turn on the auto-renewal feature on your iPhone:
On your iPhone, tap Settings. Then tap your name at the top of the screen that opens.
Tap the field at the top of the screen that says Apple ID: [your email address].