HttpRequest not working

I can access mql5's economic news with the code below.

https://help.ctrader.com/ctrader-algo/guides/network-access/?h=httprequest#performing-a-post-request

According to the example here, I can't access when I use HttpRequest. Will using WebClient cause a problem?

try {

using var webClient = new WebClient();

// Headers

webClient.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";

webClient.Headers.Add("x-requested-with", "XMLHttpRequest");

webClient.Headers.Add(HttpRequestHeader.UserAgent, "_fz_uniq=5059388315850202230");

// POST Data

var postData = new NameValueCollection

{

{"date_mode", "0"},

{"from", "2023-09-01T00:00:00"},

{"to", "2023-09-02T23:59:59"},

{"importance", "13"},

{"currencies", "262143"}

};

// Send POST Request

byte[] responseBytes = webClient.UploadValues("https://www.mql5.com/en/economic-calendar/content", "POST", postData);

string response = System.Text.Encoding.UTF8.GetString(responseBytes);

// Process Response

Print("Server Response: ", response);

}

catch (Exception ex)

{

Print($"General Error: {ex.Message}");

}