ProGCC V3 Firmware Update
You know you need to update your firmware when the configuration page prompts you like so:
Download the firmware file from this link:
To update the firmware on the ProGCC V3 all you have to do is hold the sync button while plugging the USB into your computer.
When the controller is plugged in you should see a file browser window pop up, simply drag the downloaded "PROGCC_RP2040.uf2" into the folder.
The folder should automatically close and the controller should reboot to confirm the update has happened.