Firebase Consle Script

Hi,
I Have Script From Google Firebase and I Want to add script to Invoiceplane, Where I have to add the google script,
Script is Here.

script src="https://www.gstatic.com/firebasejs/3.2.1/firebase.js"></script>
script>
  // Initialize Firebase
  var config = {
    apiKey: "AIzaSyBOCmezsxuQG4N3Iyvp_4rCeb50TRQCwgg",
    authDomain: "mdcinvoice-72f4d.firebaseapp.com",
    databaseURL: "https://mdcinvoice-72f4d.firebaseio.com",
    storageBucket: "mdcinvoice-72f4d.appspot.com",
  };
  firebase.initializeApp(config);
</script

Could you please explain what this script is doing or what it should do?

this script is to add my web app to firebase, so i can control database from firebase consle and real time tracking. and i want to load on startup.