Can't watch a movie bought through Apple TV app on iPhone, on my Smart TV

Ok. Is this perhaps for a different model TV than the LG TV UN73 series?

In late 2021, LG TV extended support for Apple TV+ to 2016 and later models that weren’t included in the initially supported model list, but these additions got a more limited edition of the app, without Store or Library (i.e. not for buy-movies).

So now there are two editions, one ‘full app’ for newer/​higher end models, and one ‘specialized/​limited app’ for slightly older models, dependent on specific model and year or release. Unfortunately not user choice.

Which exact app name and app icon do you get on this TV? With or without the “+”? The edition without the “+” should have Store and Library, but the edition with the “+” would not have that. The latter wouldn’t be able to stream your purchased movies through the smart TV app.

TVs that do not have support for the full Apple TV app, would be able to access it anyway through an HDMI-connected external streaming device that has support for this full app. E.g. through Apple TV box, Roku, Fire TV, PlayStation (4, 5), Xbox (One, One S, X, S), ‘Chromecast with Google TV’-dongle, Nvidia Shield TV box.

43UN73006LC

A 2020 4K LG TV should have the full Apple TV app with Store and Library, which would sync through a matching Apple Account.

What happens instead when you try to watch it on your smart TV? Do you get an error message? What does that say?