How to cancel Microsoft 365 Personal license purchased from Apple

Many years ago I bought a Microsoft 365 Personal license in a physical Apple Store. It was a one time purchase that is supposed to last indefinitely and there are no recurrent charges. I need to cancel it. It doesn't appear on the list of my current Apple Subscriptions but it does appear in my Microsoft account where it clearly says "Purchased from Apple". I contacted Microsoft and they indicated that it needs to be cancelled directly by Apple. How can I cancel this? Thank you everyone.