Hookup for Sharing speakers and mic through a KVM

I'm trying to set up things so both my machines, one with Windows 7 & other with Win10, share the mouse, keyboard, display, mic & speakers. I have an IOGear KVM for this purpose with a button that switches all these things from one machine to the other.

I've had it set up to share  mouse, keyboard, display for a long time but as yet haven't figured out how to share a mic & speakers. Consequently, I connect the speaker to the green 3.5mm connector on the back panel on my Win10 machine unless I really need it on my Win7 machine which is rare.

I also have a Logitech Logi Webcam to support Zoom. However, it can ONLY be used to connect the front panel since the cable is USB. The idea is when it is plugged in  it overrides the corresponding "system" devices.

Here's what I know or believe is correct:

The IOGear KVM has (USB) ports for keyboard, mouse and display. It's quite clear how they must be connected. It also has mic( pink) & speaker (green) 3.5mm ports, but I don't know what they should be connected to. That's the crux of my problem.

BTW, my monitor also has a green 3.5mm port, presumably to act as a crummy "system speaker" like the little cone speakers that used to be installed in the computer case.

But, mic and speaker can be overridden by devices plugged into the front panel. That is, when a headset is plugged into a front panel USB port the corresponding system devices are disabled.

My Logitech Logi  Webcam/mic has a USB connector and therefore can be plugged into ONLY the Front Panel. 

Any help would be appreciated.