Where do I get Autodiscover-URL in order to use skype API?

Question

Hi there

I'm going to integrate skype into a website using skype api for business to have abbility to read and send messages with Skype-for-Business-UCWA-PHP
this lib -> https://github.com/wapacro/Skype-for-Business-UCWA-PHP
 
In fact I haven't purchased business account yet.
 
And I'm curious about a couple things in the code:
http://joxi.ru/DrlRD4xT4KdMG2

So, where do I get Autodiscover-URL? Or may be I should get business account first?
And what should I put into UCWA_init( "http://myapp.example.com" )?

I saw in the code that it sends curl requests, gets responses and extract data from it. That means it shouldn't be my own domain. I believe it must be some skype verified url. But where can I see it?

Thanks a lot in advance for any help)