Use iphone to control apple tv

To use a software remote, use the Apple TV Remote in Control Center on your iPhone.

Set up the Apple TV Remote on your iPhone, iPad, or iPod touch - Apple Support

The iPhone and Apple TV have to be on the same home network already. In some situations, you may need a functional remote to help set it up with the 3rd generation model.

iTunes Remote is different. That controls for playback the music and videos in your (home shared) iTunes/Media Library on your Mac or PC, from your phone, to that Mac or to an AirPlay device. It is a free app from Apple; it has nothing to do with subscriptions, or you may be looking at a different app.

Search for the iTunes Remote in the App Store.

That’s the one you need https://apps.apple.com/br/app/itunes-remote/id284417350

This is a free app from Apple that works on your phone just like the original physical remote.