Firebase.database( ) object has no 'ref' method or 'Reference' method to call

I have started with firebase , but have run into an annoying problem for a while. When ever I create a database object with firebase.database() , when I try to call the ref method , there is no ref method available. I am using WEBSTORM IDE from JetBrains. So when i push the data , it won't go into the database. Here is my code .

firebase.initializeApp(config);
function loginclicked()
{

    var database = firebase.database()

    var ref = database.ref('Scores') ;

    var data = {"Name" :"Natesh" , "Age" : 27} ;

    ref.push(data) ;

}

Here is my data in the database :-

My project name is 'sit-notifier' , I have also set the database rules to accept all requests.