title: FCM Notification is not received by client app through node.js
body: <p>I am working on an application in which I have to send the notification to android devices from node server with the help of fcm-node/firebase-admin.Server is successfully sending the notification but client App is unable to receive it.The code is given below: </p>
  
  <pre><code>var FCM = require('fcm-node')
  
  var serverKey = require('./myapplication3-efc5b-firebase-adminsdk-haq21-361858e343.json') //put the generated private key path here    
  
  var fcm = new FCM(serverKey)
  
  var message = { //this may vary according to the message type (single recipient, multicast, topic, et cetera)
      to: 'e4rIFxa5bUo:APA91bH_eDZjZW1Fh5Ib6gI26fbS66bP7qBvRoe740FQNNox8QgUADt_nEF-7Bxze_lB5LuMA9JJcrbaGzd_VLIWaQPUwF4qWrpsixOTZAxK3YZNydLuZLXDw1SpBiYCAkYhajhUGC2l', 
     // collapse_key: 'notification',
  
      notification: {
          title: 'Title', 
          body: 'Trial' 
      },
  
      data: {  //you can send only notification or only data(or include both)
          my_key: 'my value',
          my_another_key: 'my another value'
      }
  }
  
  
  fcm.send(message, function(err, response){
      if (err) {
          console.log(err)
      } else {
          console.log("Successfully sent with response: ", response)
      }
  })
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/5b0BQ.png" alt="Output of node server"></p>