How to watch comes up when I want to watch a movie

The mentioned movie is not part of the Apple TV+ catalog, but instead available through the Store section of the Apple TV app, where supported, as an item to buy or rent.

Depending on the platform that your smart TV or TV-connected streaming device uses, buying or renting may be a bit more tangled.

2. In the US, you can subscribe to Apple TV+ on Amazon Fire TV, but you can't purchase other content from the Apple TV app. On Amazon Fire TV (in other regions), Android TV, and Sony TV devices, you can't purchase content from the Apple TV app. You can buy, rent, or subscribe on another supported device and then watch in the Apple TV app on your Amazon Fire TV, Android TV, or Sony TV device.

The How to Watch blurb was supposed to convey that. Basically, variants of the Play Store are currently excluded for transactions with Apple services.

Supported devices for transactions are: iPhone, iPad, iPod touch, Mac, PC with Apple TV app, Apple TV box, Roku, PlayStation (4, 5), Xbox (One, One S, X, S), LG TV, Samsung TV, Vizio TV.

Once the transaction is done, the content will be available through the linked Apple ID account, on any of your devices with the Apple TV app, including Fire TV, Android TV, and Google TV platforms. See the Library in the app to find past purchases.

Thats the only reason I purchased apple plus because I wanted to watch this movie

Not sure why you thought this title would be included with an Apple TV+ subscription. Where did you find your information?

About Apple TV+ - Apple

Apple Originals - Apple TV+ Press

List of Apple TV+ original programming (episodic/series) - Wikipedia

List of Apple TV+ original films - Wikipedia

Buy or rent movies do not depend on an Apple TV+ subscription. Buy or rent movies are equally available to subscribers and non-subscribers, and for the same price.

Im very disappointed with apple and will not renew with them

If none of the Apple TV+ movies and TV shows have your interest, then it seems logical to end this subscription.

To cancel a subscription with payment through Apple, do as any one of these describes (pick one):

- On third party devices with the Apple TV app: Manage subscriptions in the Apple TV app - Apple Support

- On any of your Apple devices: How to cancel a subscription from Apple - Apple Support

- On the web: How to cancel Apple TV+ - Apple Support

- On a PC with iTunes: Use a Windows PC to cancel subscriptions from Apple - Apple Support

If you subscribed through Amazon, then cancel there.