HDMI out to AVR while connected to a 7" display possible?

I have an official Raspberry Pi 7" display connected to a Pi 4. Is it possible to get it to play audio from my Denon AVR HDMI input?

In settings is doesn’t offer me the option to choose HDMI as an option and the HDMI cable is on the O connection (I’ve tried both).

Connect to Volumio via SSH and try adding


to “/boot/userconfig.txt”.

Thanks, I’ll try that and get back with results.

Edit: This added the HDMI output! Now I just can’t find my damn HDMI cable!

Edit 2: It worked, found my cable and it made me a happy camper today. Appreciate the help.