Question on how i can use voice to search for a show across apps?

I would like to be able to search for a show with the Google assistant button on the remote. when i search for a show that is on Directtv it works great. when I search for a show that is on, say Netflix or appletv it just goes to YouTube. under google assistant it only shows me to search on Netflix as the only app i can pick, but even with that on it still goes to youtube. has anyone gotten this to work? thank you