title: Firebase API is not sending push notifications when using the API
body: <p>I'm migrating from Parse to Firebase and facing a problem with our ios app.
  The Firebase API does not send push notifications to the ios app.
  This is what im sending to <a href="https://fcm.googleapis.com/fcm/send" rel="noreferrer">https://fcm.googleapis.com/fcm/send</a></p>
  
  <pre><code>{ 
   "to: "&lt;registration token&gt;",
   "priority": "high",
   "data": {
       "customId": "&lt;my custom id&gt;",
       "badge": 1,
       "sound": "cheering.caf",
      "alert": "New data is available"
    }
  }
  </code></pre>
  
  <p>And the server is returning success</p>
  
  <pre><code>{
      "multicast_id":6917019914327105115,
      "success":1,
      "failure":0,
      "canonical_ids":0,
      "results":[{"message_id":"0:1468961966677585%f0f84693f9fd7ecd"}]
  }
  </code></pre>
  
  <p>But the push is not delivered.
  If I sent the push using the Firebase Dashboard, the pushes are delivered, even if I targeting directly with the Token.</p>
  
  <p>I saw another developer complaining in another Stackoverflow question
  <a href="https://stackoverflow.com/questions/37332415/cant-send-push-notifications-using-the-server-api">Can&#39;t send push notifications using the server API</a></p>
  
  <p>I tried their solution of adding the <strong>"priority": "high"</strong>, it did not fixed the issue. But it gave me a clue: They are also using the dev/sandbox push certificate.</p>
  
  <p>My suspicion is that the Dashboard can use the ios Development certificate, but the API can not. The problem only happen on the ios device, since the android app are getting the pushes through API.</p>
  
  <p>Is anyone able to send pushes using the API and the development certificate?  </p>