How do I unsubscribe?

See this, View, change, or cancel your subscriptions - Apple Support

Just wanted to clear up something. When you state "Apple TV" then did you mean the subscription to Apple TV+ ? There is the TV app from Apple which lists all the programming based on your viewing and then in addition to that is the Apple TV+ subscription. If you are talking about the latter then please follow the direction that was give to you in the message posted by Chrisj4203 above. Thanks.

Axel F.