Just Dance Now only supports the 1st generation of Apple TV/Siri Remotes and older Apple TV Remotes. The 2nd generation of Apple TV/Siri Remotes is not supported due to hardware limitations; however, you can use the new Apple TV Controller feature in the Just Dance Now mobile app to connect to Apple TV and play Just Dance Now.
To connect your phone as the Apple TV dance controller, you need to enter the Master Code and the Dance Room number in the Just Dance Now mobile app. The Master Code is shown below the Dance Room number in Just Dance Now on your TV screen. Enter both of these in the Apple TV Controller option in your mobile Just Dance Now app.
The first phone to connect using the Apple TV Controller option will become the Dance Room master on Apple TV. If a mobile phone is already connected as the Dance Room master then all the others who try to connect their mobile phones using the Apple TV Controller option will automatically join the Dance Room as secondary users.