I can't correctly compose an xhr request to get a list of study groups

The point is to make an xhr request that will download a list of groups from the site, like what a browser does

Network tab in firefox browser

static private readonly Regex _code = new(@"request\.setRequestHeader\('X-CS-ID', '(?<code>[\w\d]+)'\);");static private readonly string _linkGroupList = "https://www.asu.ru/timetable/students/";static private HttpClient _httpClient = new();static async Task Main(string[] args){    HttpRequestMessage messenge = new HttpRequestMessage(HttpMethod.Get, _linkGroupList +"12/");    messenge.Headers.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7");    messenge.Headers.Add("Accept-Language", "ru-RU,ru;q=0.9");    messenge.Headers.Add("Upgrade-Insecure-Requests", "1");    messenge.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36");    messenge.Headers.Add("sec-ch-ua", "\"Not;A=Brand\";v=\"24\", \"Chromium\";v=\"128\"");    messenge.Headers.Add("sec-ch-ua-mobile", "?0");    messenge.Headers.Add("sec-ch-ua-platform", "\"Windows\"");    HttpResponseMessage mes = await _httpClient.SendAsync(messenge);    string html = await mes.Content.ReadAsStringAsync();    string code = _code.Match(html).Groups["code"].Value;    Console.WriteLine(code);    messenge = new HttpRequestMessage(HttpMethod.Get, _linkGroupList +"12/");    messenge.Headers.Add("Accept", "*/*");    messenge.Headers.Add("Accept-Language", "ru-RU,ru;q=0.9");    messenge.Headers.Add("Cookie", "...");    messenge.Headers.Add("Referer", "https://www.asu.ru/timetable/students/12/");    messenge.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36");    messenge.Headers.Add("X-CS-ID", code);    messenge.Headers.Add("sec-ch-ua", "\"Not;A=Brand\";v=\"24\", \"Chromium\";v=\"128\"");    messenge.Headers.Add("sec-ch-ua-mobile", "?0");    messenge.Headers.Add("sec-ch-ua-platform", "\"Windows\"");    mes = await _httpClient.SendAsync(messenge);    mes.EnsureSuccessStatusCode();    foreach(var i in mes.Headers)    {        Console.WriteLine($"{i.Key} : {string.Join("; ",i.Value)}");    }    string res = await mes.Content.ReadAsStringAsync();    Console.WriteLine(res);}

res is empty...

I tried to build different variations of headings, including through Postman