On your Siri Remote or Apple TV Remote, press or to turn the volume up or down. If the volume doesn’t respond, follow steps to manually program your Siri Remote or Apple TV Remote for volume control. Your Siri Remote or Apple TV Remote can control volume for either your television or your receiver, not for both simultaneously. read more
Grab an old remote and use the Remote app to head to Settings > General > Remotes > Learn Remote on your Apple TV. Hit the Start button and press and hold buttons to assign each one a function. It will walk you through the basic buttons first: Up, Down, Left, Right, Select and Menu. read more