I know very little about it. But from what I have learned, you must has an HDMI-ARC (audio return channel) connection between the TV and the sound system to get TV sound transmitted to the sound system. Don't know if that requires a specific type TV or not. Or if the standard Montana TV has that feature. And the sound system must also be HDMI-ARC compatible.
https://www.lifewire.com/connect-tv-...system-1846816