I think the script is looking for the right way to flash a “FP2” but it is not finding a matching device so it bails out and prints this error message (there is no matching device defined for “FP2”).
I would say screw this script and just flash the images by hand. 
Or see if someone can update this script for you. Flashing by hand is not so hard, but it’s good to know what you do. If you look at your first screenshot you can see where the images are located.
See: “Flashing images” in here: