HttpRequest.cs

 using (var client = new HttpClient())
            {
                var message = new HttpRequestMessage(HttpMethod.Post, url);

                message.Headers.Add("Authorization", authKey);
                message.Headers.Add("Audit",auditKey);
                
                message.Content = new StringContent(content, new UTF8Encoding(), "application/json");

                var response = client.SendAsync(message).Result;
                return response.Content.ReadAsStringAsync().Result;
            }