Notifications with FireBase Cloud Messaging and C sharp

I have a problem since yesterday and I want to know if it is really possible to implement it.

I have an application in C # desktop and another in Android. What I would like to do is, in the case something is done in the desktop application (be it registration, update or deletion), be notified by FireBase to my Android application.

What I could do in my tests is to notify my Android APP from a FireBase console event.

By the following code, with the credentials of my FireBase account I have sent a "notification", without receiving anything in my Android APP, but receiving an answer:

C # notification code:

private static string SendPushNotification()
    {
        string response;

        try
        {
            // From: https://console.firebase.google.com/project/x.y.z/settings/general/android:x.y.z

            // Projekt-ID: x.y.z
            // Web-API-Key: A...Y (39 chars)
            // App-ID: 1:...:android:...

            // From https://console.firebase.google.com/project/x.y.z/settings/cloudmessaging/android:x,y,z
            // Server-Key: AAAA0...    ...._4

            string serverKey = "AAA......5"; // Something very long
            string senderId = "18......7";
            //string deviceId = "dj9...c:APA...    .....WTw"; // Also something very long, 
                                                            // got from android
            string deviceId = "/topics/android";             
                                                            // Use this to notify all devices, 
                                                            // but App must be subscribed to 
            // topic notification
            WebRequest tRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");

            tRequest.Method = "post";
            tRequest.ContentType = "application/json";
            var data = new
            {
                to = deviceId,
                notification = new
                {
                    body = "Greetings",
                    title = "Augsburg",
                    sound = "Enabled"
                }
            };

            var serializer = new JavaScriptSerializer();
            var json = serializer.Serialize(data);
            Byte[] byteArray = Encoding.UTF8.GetBytes(json);
            tRequest.Headers.Add(string.Format("Authorization: key={0}", serverKey));
            tRequest.Headers.Add(string.Format("Sender: id={0}", senderId));
            tRequest.ContentLength = byteArray.Length;

            using (Stream dataStream = tRequest.GetRequestStream())
            {
                dataStream.Write(byteArray, 0, byteArray.Length);
                using (WebResponse tResponse = tRequest.GetResponse())
                {
                    using (Stream dataStreamResponse = tResponse.GetResponseStream())
                    {
                        using (StreamReader tReader = new StreamReader(dataStreamResponse))
                        {
                            String sResponseFromServer = tReader.ReadToEnd();
                            response = sResponseFromServer;
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            response = ex.Message;
        }

        return response;
    }

Answer

"{\"message_id\":82xxxxxxxxxxxxxxxxx}"

"{\"multicast_id\":8580xxxxxxxxxx,\"success\":1,\"failure\":0,\"canonical_ids\":0,\"results\":[{\"message_id\":\"0:152xxxxxxxxx%0000000000000000\"}]}"

As far as I have been able to review the documentation, there is nothing official for C #. Am I on the right track? Is it possible to do this or do I have to do something else?

Punctual, I need to notify changes in my Android APP from my C # application.

I have:  - A WinForm application made in Visual Studio C #  - An account in FireBase CLoud Messaging  - An APP made in Android Studio.

Thanks for any help.