Thanks! I set the Dash USB as programmer, and it compiled.
Unfortunately, the Arduino IDE asked if I wanted to upgrade the firmware, to which I clicked “Yes”.
When it tried to upload the Arduino script, it said it couldn’t find the serial port, which is now grayed out in the Arduino menu. Also, the LED between the two buttons on the Dash is now fast blinking when the USB cable is plugged into my laptop.
It’s looking like the firmware upgrade may have failed. How can I fix this?