<script src="https://www.gstatic.com/firebasejs/4.5.2/firebase.js"></script>
<script>
  // Initialize Firebase
  var config = {
    apiKey: "AIzaSyAKCIEhZZ9WDGtQp2zAdLP7uzd06PK2NVU",
    authDomain: "appcombi-7e2c7.firebaseapp.com",
    databaseURL: "https://appcombi-7e2c7.firebaseio.com",
    projectId: "appcombi-7e2c7",
    storageBucket: "appcombi-7e2c7.appspot.com",
    messagingSenderId: "490513766831"
  };
  firebase.initializeApp(config);
</script>