Firebase playground

HTML

<script src="//cdn.firebase.com/js/client/2.2.1/firebase.js"></script>
<a id='add'>add user</a>
<div id='data'>
data here
</div>
<script src="https://www.gstatic.com/firebasejs/5.5.9/firebase.js"></script>

JavaScript

// Initialize Firebase
var config = {
  authDomain: "iqy-dev-vicken.firebaseapp.com",
  databaseURL: "https://iqy-dev-vicken.firebaseio.com",
  projectId: "iqy-dev-vicken",
  storageBucket: "iqy-dev-vicken.appspot.com",
  messagingSenderId: "99533987998"
};
firebase.initializeApp(config);
  
console.log('--')

var query = firebase.database().ref('/notifications/learner01/').orderByChild('channel/title').equalTo('General');

query.once("value", function(snapshot) {
  console.log('---value', snapshot.val());
}, function (errorObject) {
  console.log("The read failed: " + errorObject.code);
});