Make sure your MacBook and TV are on the same Wi-Fi network
On your MacBook, click the Control Center icon in the menu bar
Click Screen Mirroring
Select your TV from the list of available devices
Enter the AirPlay code shown on the TV if prompted
To stop mirroring, open Control Center again and click Screen Mirroring
Select Stop Mirroring
If your TV does not appear, make sure AirPlay is enabled on the TV
If needed, connect your MacBook to the TV with an HDMI cable and adapter
On your MacBook, go to System Settings
Click Displays
Select the TV or external display
Choose Mirror Display if available