I have a TCL Roku TV and I am trying to setup surround sound. However, I can't figure out a way to get it to work. I can plug an HDMI cord from my receiver into the ARC spot on the TV but that is labeled HMDI3. In order for sound to pass through to my receiver I need to choose HDMI3 on the TV home screen. However, We watch all our TV with the built-in Roku (YouTube TV, Netflix, etc).
So how do I tell the TV to output the sound on HDMI3 when we are actually not watching anything on HDMI3? I am at a loss.