Make sure your iPhone and TV are connected to the same Wi-Fi network
Open Control Center on your iPhone
Tap Screen Mirroring
Select your TV from the list
Enter the AirPlay code on your iPhone if prompted
To stop sharing, open Control Center again and tap Stop Mirroring
If your TV does not support AirPlay, connect an Apple TV or use a compatible streaming device
If needed, use a Lightning to HDMI adapter and HDMI cable to connect your iPhone directly to the TV