Movies not playing

It seems that this title is available to purchase (buy or rent) from Apple’s content Store. It is not available just from an Apple TV+ subscription.

Unfortunately, purchases through the Apple TV app are currently not supported on Fire TV, on Android TV, or on Google TV [2]. Therefore, you will have to do the financial transaction on a different supported device (e.g. iPhone). Once purchased, the content will be available on any of your devices through the matching Apple ID account. The “How to Watch” blurb was supposed to convey that.

Can I not watch movies on my laptop then??

Buy or rent movies are available in the Apple TV app for Windows (but not on the tv.apple.com website). Computers are valid as one of these ‘different supported devices’ that do not use the Google Play Store or a variant of that. Apple TV app user guide for Windows - Apple Support

… both my tvs are smart tvs

Fire TV, Android TV, Google TV are currently excluded for financial transactions for this app, but other smart platforms are fully supported: LG TV, Samsung TV, Vizio, VIDAA, Roku TV.

Several TV-connected streaming devices are also supported for transactions: Apple TV box, Roku, PlayStation (4, 5), Xbox (One, One S, X, S).

As mentioned before, once the transaction is done, the purchased content would also be available on Fire TV.

Good luck!