Apple TV Control your home entertainment system with the Siri Remote
You can configure the Siri Remote to turn your TV on or off, change the input to your Apple TV, and even control the volume.
Use the Siri Remote to turn your TV on or off. In Settings 
, go to “Remotes and Devices” > “Turn On Your TV with Your Remote.”
Use the Siri Remote to control the volume of your TV or receiver. In Settings , go to “Remotes and Devices” > Volume Control.
Note: These settings may not work with all devices. For more information see Apple TV Support.