How to control tv soundbar with Apple TV Remote

If your sound bar supports HDMI-CEC (may be named something different by the sound bar manufacturer. Look for Sync or Link in the feature name) turn it on in the sound bar settings, then in the Apple TV Settings ➜ Remotes & Devices ➜ Volume Control set it to auto.

If all works as expected, the volume buttons on the Apple TV remote should control the Sound Bar volume. It should also turn on and off when you turn on or off the Apple TV.

click here ➜ Control your TV and volume with the Siri Remote - Apple Support