Pair AirPods to tvOS 11
Pick up your AirPods charging case and open it.
Press and hold the pairing button on the back of the case.
Launch Settings on your Apple TV
Click on Remotes and Devices.
Click on Bluetooth.
Select your AirPods from the list.

https://support.apple.com/en-us/HT207010

https://discussions.apple.com/message/31128330#31128330

https://www.imore.com/how-pair-your-airpods-apple-tv-android-and-other-bluetooth-devices