请求来自邮递员的作品，但不是来自C＃代码的作品

Question

每当我将HTTP正文添加到Http请求中时，我都会得到401响应代码。相同的要求是正常工作的邮递员。

    var client = new RestClient("http://10.10.2.10:9000/haproxy_stats");
    client.Timeout = -1;
    var request = new RestRequest(Method.POST);
    request.AddHeader("Authorization", "Basic QURNSU46UGFzc3dvcmQtMTIzNA==");
    request.AddHeader("Content-Type", "application/x-www-form-urlencoded");
    request.AddParameter("s", "server2");
    request.AddParameter("action", "ready");
    request.AddParameter("b", "#2");
    IRestResponse response = client.Execute(request);
    Console.WriteLine(response.Content);