plivo demo web client is not working

I am planning to integrate plivo sdk to my business. I need both Android and web integration but web one very first. Therefore I have tried to test demo application they have provided with below URL. http://ift.tt/2fNKuJN

I used to logging successfully and but i cannot get a voice call to mobile number using web demo. Can some one give me an ideas on this why it is not working or i m wrong ?

Thanks