by Fabrice de Chaumont / 16 June 2023 

In the arduino IDE:
in preferences, additional boards manager urls, add this one: https://adafruit.github.io/arduino-board-index/package_adafruit_index.json

The FED 3 is driven by a Feather MO board.

in the board manager, get the SAMD Board package with Feather M0 in the description
download the fed3 library

connect the FED to the usb port that is inside the fed (about at the middle of the device) not the one on the side.
switch on the device with the switch on the side
to open the programming port, double click on the switch close to the inner usb port on the feather M0

and you are now able to upload content to fed

more info here: https://learn.adafruit.com/adafruit-feather-m0-basic-proto/setup
