I’m trying to sign in Apple TV for my smart tv through my IPhone

Hello and welcome to Apple Support Communities dare76,

We see that you have a question about using the Apple TV app on your Smart TV. We’d be happy to provide you with some information to help.

If you’re trying to watch the Apple TV app on your Smart TV, you can using the link below to select your Smart TV brand and then get started with watching the Apple TV app.

Watch on a Smart TV 

If you’re referring to using AirPlay to stream the Apple TV app from your iPhone to your Smart TV, the resource below will guide you through those steps.

Use AirPlay to stream video or mirror the screen of your iPhone, iPad, or iPod touch 

If neither of these are what you’re referring to, respond back with some more details.

Thank you for using Apple Support Communities.