If this is a subscription then please read this link to learn "How to cancel a subscription from Apple" Click here --> https://support.apple.com/HT202039
Note:
• "If you don’t see Cancel Subscription, then the subscription is already canceled and won't renew." The "Expires" date means the current subscription will just run until then.
• Deleting an app does not cancel a subscription.
• If you don’t cancel trials more than 24 hours before your renewal date, your subscription might renew.
• If you don't have an Apple device, see the options near the very bottom of the support document
"If the subscription that you want to cancel is not listed", click here --> https://support.apple.com/HT212052
If you still can't find a subscription, contact Apple Support using the link at the end of the support article.
If you still have problems or this is just a regular app for which you wish a refund:
Report A Problem; click here --> https://reportaproblem.apple.com/?s=6
Or click here --> https://support.apple.com/choose-country-region/media-services Select your country, then a product.
See how to set use and purchasing restrictions on a device: Use Screen Time on your [or a child's] iPhone, iPad, or iPod touch - https://support.apple.com/HT208982