If you are lucky enough to find a CM4 Pi processor with eMMC memory and a Pi IO board, here is how you flash it:
On your Windows machine, download the Windows installer HERE. Install that on your Windows computer.
Jump pins to "disable eMMC Boot" (far left two pins together)
Plug a micro USB to USB between the IO slave port and the Windows USB port.
Run the RPBoot.exe application on the Windows computer.
Power up the IO board.
The Windows computer should soon display the new drive for the Pi USB Drive.
Using Etcher on the Windows computer, flash the myServer 6 Master image to the CM4 eMMC memory. Choose the Pi USB Drive as the Target. This will take around 25 minutes to flash and validate due to the low speed of the micro USB.
Once the flash is completed, power down the IO board, disconnect the USB, unplug the J2 Jumper and reboot.
Your IO board should then boot to myServer 6!
Identifying CM4 modules:
The pic above references a Wifi enabled (the silver box) that has the external antenna connection (top left, under the mounting hole) and likely 32 Gig eMMC memory (the black flat module to the left of the CPU and the same module above the CPU).