I have read the manual. Sorry, I should have given more info in my initial post.
On the receiver, in Settings -> HDMI Settings, 'Control for HDMI' is 'On'. And 'D' is connected (this is the HDMI cable running from the receiver's "TV Out/ARC" port to the TV's "HDMI (ARC)" port).
On the TV, in Settings -> Audio -> Audio output, the 'Auto' setting is selected which states "Unless using headphones, audio will be sent to the best output available: 1. ARC 2. TV speakers". Currently, sound comes via the TV speakers.
If I set it to "ARC (HDMI 2)", it says, "ARC (HDMI 2): Inactive. System audio control: Inactive To use your home audio system, connect an HDMI cable from the TV's ARC port (HDMI 2) to the ARC/eARC port on you home audio system. Note: You can control the volume with your TV remote. TV speakers are turned off."
So it doesn't look like it is recognizing the ARC connection?? Any suggestions? Try a different cable, even though this one is new? It was a cheap one (Onn brand).
Side note: I have a Blu-ray player connected via HDMI to the receiver and when I turn it on and set the receiver to 'BD', the video does display to the TV, so the HDMI cable from the receiver to the TV does work.