Subscription to Apple TV+ not recognized on Amazon Firestick?

I’m trying to watch the next episode of a show with my Amazon Firestick but on the screen there’s just a button says “How to Watch”. When you click it, it takes you to a page that has the Apple TV+ logo then says “You can buy, rent, or subscribe in the Apple TV app on iPhone, iPad, and other streaming devices.”

I have the Apple One subscription where Apple Music, Apple TV+, Arcade, and iCloud are combined and have been for a while. Why am I seeing this notification? How can I fix this? Thank you.