Adafruit Feather nRF52840 Express

Either use the drag and drop UF2 method or more steps involved - Arduino uploading method. For the UF2 method

• Download the UF2 file for the feather nrf52840 express board in the current release__

• Double click that reset button. You will then get a USB drive on your computer. Drag and drop the UF2 file to the root of that drive.

• It SHOULD disconnect from your Computer if successful and the light should change colour to Green

• More details see the steps here

Or the Arduino uploading method.

• Check the setup of your Arduino IDE (remember we're using the nRF52840 board!)
• Upload the sketch to your feather.
• Run the server side code

• Done!