c# - WebRequest Not working on IIS but works in Visual Studio debugging or postman

Question

.net core 3.1 application running under IIS 8.5 win 2012 R2

I try to push notification using WebRequest through this website but I get timeout. it's flustrating because when i write the same WebRequest in Postman or even in debugging mode in Visual Studio it's working!

Problem is when the Application is trying to post webrequest to fcm.googleapis.com

1. User fills up form,
2. User POSTs to web application,
3. Application creates another WebRequest with data from user post to fcm.googleapis.com and submits POST form in order to push notification to android devices

Web Form for users

[HttpPost]
public async Task<IActionResult> Create(CreateViewModel vm)
{
    var request = new CreateRequest()
    {
        Author = String.IsNullOrEmpty(User.Identity.Name) ? "Guest" : User.Identity.Name,
        Description = vm.Description, 
    };
    var response = await _notificationService.Create(request);
    vm.IsValid = response.IsSuccessfull;
    vm.ShowBaseMessage = true;
    vm.BaseMessage = response.Message;
    return View("_CreateModalPartial", vm);
}

This data is passed to service which is responsible for submiting notifications

WebRequest for notification

try
            {
                var tRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");
                tRequest.Method = "post";
                tRequest.Headers.Add(string.Format("Authorization: key={0}", "apiKey"));
                tRequest.Headers.Add(string.Format("Sender: id={0}", "senderId"));
                tRequest.ContentType = "application/json";
                var payload = new
                {
                    to = clientToken,
                    data = new
                    {
                        author = author,
                        description = description
                    }

                };

                string postbody = JsonConvert.SerializeObject(payload).ToString();
                Byte[] byteArray = Encoding.UTF8.GetBytes(postbody);
                tRequest.ContentLength = byteArray.Length;
                using (Stream dataStream = await tRequest.GetRequestStreamAsync())
                {
                    dataStream.Write(byteArray, 0, byteArray.Length);
                    using (WebResponse tResponse = tRequest.GetResponse())
                    {

                        using (Stream dataStreamResponse = tResponse.GetResponseStream())
                        {
                            if (dataStreamResponse != null)
                                using (StreamReader tReader = new StreamReader(dataStreamResponse))
                                {

                                    String sResponseFromServer = tReader.ReadToEnd();
                                    //result.Response = sResponseFromServer;
                                }
                        }
                    }
                }
            }
            catch(Exception e)
            {
                _logger.LogWarning(e.Message);
            }

ALL TESTED DIRECTLY IN SERVER.. not external PC, I have even installed Visual Studio in win 2012 R2 to debug in there but the problem doesnt show up while dubbing.. only after publishing it to IIS 8.5

question from:https://stackoverflow.com/questions/65858111/webrequest-not-working-on-iis-but-works-in-visual-studio-debugging-or-postman

Answer 1

Waitting for answers