If I were you, I would go to this page and talk to him directly.

https://github.com/Tachyon

I sent an email, but no reply ...

Can you help me...??

The method 'site.test' has been implemented in start.php in the plugin that you downloaded. You will have to install it to your Elgg in order to use the method.

Here you can find the instructions how to expose your own methods to the API:
http://docs.elgg.org/wiki/Web_Services#Building_out_your_API

Hope this helps.

Part of the elgg installation is telling the database where the site lives - a url.  If your URL is 127.0.0.1 or localhost then the site won't work externally as all assets will try to load from that url.

My advice - if this is just a test server get a url through dyndns or similar service and use that.

Thank you! But I have to use my server for the Thesis. How do I change the paths?