How can I use my Apple watch to control my new 4th gen Apple TV?

I upgraded my Apple TV to the new 4th generation with Siri. However, it seems I can no longer use my Apple watch to control it. Is there a new app I can download for this? If not, why don't these two current Apple products no longer work together? Will this be fixed, or is there a workaround?

Often the kids will loose the remote, so being able to using other devices for control is very handy.

-Geert

PS. I'd love a "find my remote" feature, though I'm not sure the remote can make sound 😟