Any workaround to MBAir not supporting HDMI ARC?

I have my MacBook Air connected to my LG smart TV by a USB-C to HDMI cable. The TV and my stereo receiver are connect by HDMI cables using the HDMI ARC ports. But I can’t listen to things played from my MBAir using the receiver because MacOS doesn’t support/allow/actively blocks HDMI ARC. If I want to listen using the TV’s speaker - no problem. But I want to listen via the stereo. Is there a solution to this? I can’t use Airplay because my wifi connection is too weak (2MB/s average). Content originating on the DVD player play fine using HDMI ARC (picture on TV, sound thru stereo).