C# FCM for Android Push Notification

Question

I am trying to use FCM for pushing notifications to Android device but it seems that I am missing something. These are steps that I've followed

1. Create new project in https://console.firebase.google.com
2. From Settings -> Cloud Messaging tab, I got Server key and Sender Id

3. I used this code

       var regId = "device id";
       string SERVER_API_KEY = "Firebase Server key";
       var SENDER_ID = "Sender ID";
       var value = "Test Notification";
       WebRequest tRequest;
       tRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");
       tRequest.Method = "post";
       tRequest.ContentType = " application/x-www-form-urlencoded;charset=UTF-8";
       tRequest.Headers.Add(string.Format("Authorization: key={0}", SERVER_API_KEY));
   
       tRequest.Headers.Add(string.Format("Sender: id={0}", SENDER_ID));
   
       string postData = "collapse_key=score_update&time_to_live=108&delay_while_idle=1&data.message=" + value + "&data.time=" + System.DateTime.Now.ToString() + "&registration_id=" + regId + "";
       Console.WriteLine(postData);
       byte[] byteArray = Encoding.UTF8.GetBytes(postData);
       tRequest.ContentLength = byteArray.Length;
   
       Stream dataStream = tRequest.GetRequestStream();
       dataStream.Write(byteArray, 0, byteArray.Length);
       dataStream.Close();
   
       WebResponse tResponse = tRequest.GetResponse();
   
       dataStream = tResponse.GetResponseStream();
   
       StreamReader tReader = new StreamReader(dataStream);
   
       string sResponseFromServer = tReader.ReadToEnd();
   
   
       tReader.Close();
       dataStream.Close();
       tResponse.Close();
   

I always get Mismatch Sender Id error. Am I missing any steps? or do I have to do something on mobile app?

Answer 1

I found the error. As a back-end developer I worked on C# part only. There is one more step to be done from mobile application side. Mobile app should allow receiving messages from list of Sender Ids so the one that I use in my C# code must be allowed from mobile app side. Once I did that it worked