Connect your Mac and TV to the same Wi-Fi network
On your Mac, click the Control Center icon in the menu bar
Click Screen Mirroring
Select your TV or AirPlay-compatible device
Enter the AirPlay code shown on the TV if prompted
To stop mirroring, open Control Center and click Screen Mirroring again, then select Stop Mirroring
If your TV does not support AirPlay, connect a compatible HDMI adapter from your Mac to the TV
Set the TV to the correct HDMI input
On your Mac, go to System Settings
Click Displays
Choose the TV as the display or enable mirroring if available