Can't connect to screen mirroring?

I have a Samsung 5 Series Smart TV, and for some reason it's not showing up on screen mirroring. I have an iPhone X.

And ideas?

Only Apple devices will show up in the screen mirroring such as the Apple TV

Read the owner's manual. Or call Samsung for advice.

Either get an android phone, preferably the Samsung galaxy or get an Apple TV.

Both must be on the same network. Get a casting app for an iPhone, and check settings in that Samsung TV. You might need a MiraCast or some other Apple device to connect to the TV.