4
Send it to the board
The template leaves the pin as a placeholder, so put in a real GPIO number for your board. Then, marked 1 on the picture, choose the board in the Device list and press Connect; marked 2, press Upload to Device and then Script Start. The script reaches the board in a couple of seconds over an encrypted link — nothing is compiled, so nothing can fail to compile.
A wrong line stops the script and says why in the terminal. Fix it and send again — the board stays online the whole time.