var client = new System.Net.Http.HttpClient();
var response = await client.GetAsync("https://www.igromania.ru/");
response.EnsureSuccessStatusCode();
var responseBody = await response.Content.ReadAsStringAsync();
var headers = response.Headers;
headers
. А как оттуда куки вытащить? var setCookieHeaders = headers.Contains("Set-Cookie")
? headers.GetValues("Set-Cookie")
: Array.Empty<string>();