Screen sharing between iPhone and TV to view Apple TV

AirPlay requires an AirPlay receiver. That means an Apple TV set-top box or an AirPlay-enabled smart TV.

How to AirPlay video and mirror your device's screen - Apple Support

Using HDMI cables requires an HDMI adapter for the iPhone.

The Apple TV+ streaming service is blocked for use with HDMI adapters, or for use with AirPlay to an Apple TV (2nd generation) model. Devices you can use with the Apple TV app and Apple TV+ - Apple Support

For Airplay, and if your Tv supports it, make sure the Airplay option is turned in on your TV: https://www.samsung.com/us/support/answer/ANS00082643/

For the HDMI cable, you need to select the correct input on your TV the iPhone is plugged into. The TV will not automatically switch to it.

Hard to provide any suggestions without any details.

What make/model of TV exactly?

What connection options have you tried? How are you trying to connect the iPhone and Tv?

What happened when you tried them?

Did you get an error?