3D FlipBook - Book Directory

Hi - when I point the url in the code below from "books/pdf/testname.pdf" to a new URL to access our PDF files, the reader will not load these pdf files. If I also change the root folder name from "3d-flip-book" - it also stops working.

What file (if any) can I modify so we can access our PDFs on our server and use a url name that works for us?

   $('#container').FlipBook({
     pdf: 'books/pdf/testname.pdf',