Angular is not defined on Cloud 9

Hi campers,
I forked this project , and try to run it on cloud 9. Somehow, i got warning that angular is not defined. I followed the set up steps, all I can get is HTML running, no angular features.
Can anyone show me how to run this application?

  1. open index.html
  2. goto < head > section
  3. change all srcs from http to https, e.g.:
    …src=“”… => …src=“”…
  4. right click on index.html in the Workspace tab, select Preview