I found a direct link to their dev server (probably). I don't think Stunna would like to make it public.
For the Devs: So far I have found NO sign of an API, bad. (Or maybe they are still building it)
Hahaha, impressed you found that. API is being finished still. The PD you found isn't the most recent version, just something our dev tossed up when we finished our design a little while back.
That's probably the reason why nothing was working.