Those are the installation instructions.
I created a directory called 'dada_files' and when I point the $FILE variable to it, I get an Error 500. When I point it to something that has actual files in it, I get a 400. That leads me to believe they did not want me to make an empty directory named dada_files so I'm supposed to point it somewhere specific.
The problem is, they don't tell me specifically where they want me to point to. There's an external directory with several folders in it, and then there's a 'DADA' directory. I've tried linking straight to the external and to the interior DADA directory and neither works. I just get 404.