Make user node in firebase

user_record_on_register.js

//Assuming you're already in an angular controller...
$scope.user = {};
//$scope.user will get filled with "email" and "password" keys
var enteredUsername = angular.copy($scope.username);

$scope.register = function() {
    var ref = new Firebase("https://<YOUR-FIREBASE-APP>.firebaseio.com");
    var user = angular.copy($scope.user);
    
    ref.createUser({
      email    : user.email,
      password : user.password
    }, function(error, userData) {
        
      if (error) {
        console.log("Error creating user:", error);
      } else {
        console.log("Successfully created user account with uid:", userData.uid);
        ref.child('users').child(userData.uid).set({
            username: enteredUsername
        });
      }
      
    });
};