My subscription won’t work on my tv

I use a fire stick

Thanks, that is the info that I was looking for.

But even though I have a subscription to Apple TV only some films play … but on my iPhone all works

In the Apple TV app on Fire TV devices, you should be able to sign in through the in-app Settings, using the matching Apple ID account. Then your Apple TV+ subscription content becomes accessible, as well as previous iTunes Store purchases (buy/rent) in your Library linked to that same Apple ID account.

Apple TV app user guide for smart TVs and third party streaming devices - Apple Support

↳ Apple TV+ in the Apple TV app - Apple Support

↳ Library in the Apple TV app - Apple Support

(Re-)subscribing through Amazon Fire TV would be separate and wouldn’t be linked to the same Apple ID as on your iPhone. So don’t do that if you already subscribed on an Apple device. Just sign in through Settings with your existing Apple ID.

If the issue persists after all that, then please contact the Apple Support staff.

What make and model smart TV is this for? Does it have the Apple TV app or Apple TV+ app?

If you are using an external HDMI connected streaming device with the Apple TV app, then that would be important to know. If applicable, which make and model?