Apple TV casting

The recommended way is to stream using the Apple TV box, connect to a TV.

Select not-too-old smart TV may support the Apple TV app among their smart apps. Unsupported TVs may connect an external streaming device that supports the Apple TV app.

List of Apple TV app-supported smart TVs and third party streaming devices - Apple

Get the Apple TV app or Apple TV+ app on your smart TV or streaming device - Apple Support

All the ways to watch Apple TV+ - Apple Support

You may be able to stream from iPhone to TV or TV-connected streaming device using AirPlay. Select not-too-old smart TVs and third party streaming devices may support the AirPlay protocol.

List of AirPlay 2-enabled TVs and third party streaming devices - Apple (scroll down to AirPlay 2)

List of AirPlay 2-enabled TVs and third party streaming devices - Apple (similar list)

You may also be able to connect an iPhone directly to a TV using an HDMI adapter. (Untested by me.)