The header on the Dispenser board is not populated to allow for much more rapid production programming via testpoints. You can use a pogo pin header adapter to continue to not need headers on the board: https://www.sparkfun.com/products/11591
Alternatively, you can solder a header to each board that needs to be re-programmed: https://www.sparkfun.com/products/12807
Both methods require some soldering, so if you don't have a soldering iron, you'll have to find a friend who does or go to your local maker space.
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