How can I hide/remove the sidebar on my Apple TV?

For what browser?

The Safari browser has a sidebar icon in the toolbar to hide the sidebar, usually to the right of the red-yellow-green buttons, although that can be arranged differently.

The Firefox browser has an ‘X’ close button in the sidebar to hide the sidebar.

I don’t think that the Chrome browser has a sidebar on the left.

Regardless of the sidebar showing or not: When the playback window isn’t full screen, then you can click the full screen icon to go full screen. Use the Escape button on your keyboard to exit full screen.

Find it in the bottom-left-corner of the playback window, when the controls are overlayed.

The Safari sidebar icon in the toolbar works for Safari, not the Apple + website.

The Apple TV+ website doesn’t present anything to the side for me. The browser playback is full screen by default. Not sure what you are referring to, if not the browser sidebar.

Perhaps we can be enlightened by a screenshot?

>> For what browser?

If not using Safari, then what other browser are you using?

On modern Macs and other Apple devices, one would presumably use the Apple TV app, not the website through a browser. I feel like some important detail has not been mentioned yet.