Mapping 5.1 Channels

Hello All,

I'm using Audition v.25.0.0.47 on a Windows 11 PC, and I'm having problems with mapping 5.1 channels.

My PC is is connected to a Denon receiver. In the Audition audio hardware settings I have the default output and the clock set to my home theatre speakers. That's the Denon. But when I go to channel mapping, it only has options for the L and R channels. Everything else is unavailable. I've been through every option I can find, and have watched numerous tutorials over the last few days, and I cannot figure out what I'm doing wrong. Any assistance is appreciated.

thanks!