Accessing Apple TV ?

I can watch Apple TV on my iPhone, but I get an error message for watching on my tv

Please tell us, what did that error message say exactly?

LS03T,

Is this issue happening with the Apple TV app on your Samsung TV? Did you manage to sign in to the Apple TV app, through the in-app Settings (⚙️) with your Apple ID account that has the Apple TV+ subscription or iTunes Store purchases linked to it?