Question

I want to make my C# application to be able to send an http request and receive the answer at runtime

an explanation from the website I want to request from is HERE

I don’t have any experience with that before, so I’m a little confused about the JSON, XML stuff
I know I’ll need an XML parser or something like this to understand the request

Answer 1

Making a HTTP request is very simple if you don’t want to customize it: one method call to WebClient.DownloadString. For example:

var client = new WebClient();
string html = client.DownloadString("http://www.google.com");
Console.WriteLine(html);

You will need to build the correct URL each time as per the documentation you link to.

If you use the example code above to talk to your API, html (which is really the response data in general) will contain either XML or JSON as a string. You would then need to parse this into some other type of object tree so that you can work with the response.