See the full tutorial at https://learn.adafruit.com/gryo-marble-maze/
The code.py file should be copied onto the CIRCUITPY flash drive that appears when you plug the CircuitPlayground Express into your computer via a known good USB cable.
If the only drive name you get is named CPLAYBOOT, CircuitPython may not be loaded on the board. You can load CircuitPython as per this guide. Then you should be able to see the CIRCUITPY drive when connected via USB.
CircuitPython resources are at https://CircuitPython.Org/
Code written by Dano Wall and Anne Barela for Adafruit Industries.
MIT License, please attribute.
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