title: Firebase can not send push notification to android app
body: <p>I am successfully sent push notifications to FireBase Cloud Messaging(FCM) from server in order to send them to android device. But I don't know why FCM does not send those notifications to device.</p>
  
  <p>My code is as below,</p>
  
  <p><strong>Notification to FCM from server(C#)</strong></p>
  
  <pre><code>public static void SendPushNotification()
          {
              string serverKey = "AAAA...z";
  
              try
              {
                  var result = "-1";
                  var webAddr = "https://fcm.googleapis.com/fcm/send";
  
                  var httpWebRequest = (HttpWebRequest)WebRequest.Create(webAddr);
                  httpWebRequest.ContentType = "application/json";
                  httpWebRequest.Headers.Add("Authorization:key=" + serverKey);
                  httpWebRequest.Method = "POST";
  
                  using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
                  {
                      string json = "{\"to\": \"f..A:..p_G\",\"data\": {\"message\": \"This is a Firebase Cloud Messaging Topic Message!\",}}";
                      streamWriter.Write(json);
                      streamWriter.Flush();
                  }
  
                  var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                  using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
                  {
                      result = streamReader.ReadToEnd();
                  }
              }
              catch (Exception ex)
              {
                  Response.Write(ex.Message);
              }    
          }
  </code></pre>
  
  <p><strong>My response for the above request</strong></p>
  
  <p>{"multicast_id":5002368547300,"success":1,"failure":0,"canonical_ids":0,"results":[{"message_id":"0:14200031%09c4rrr5787egg"}]}</p>
  
  <p>I am assuming that once FCM receives new notifications, it will push those notifications to respective android devices. </p>
  
  <p>But for me, it is not working.</p>