Can't get facebook username field

i tried a lot of times get the username field insteal a number. but even looking for docs on the web about the related plugin i can´ t get. i apreciate if someone could help me to implement this in my code:

$scope.loginFacebook = function(){
  //Browser Login
  if(!(ionic.Platform.isIOS() || ionic.Platform.isAndroid())){
 
    Parse.FacebookUtils.logIn(null, {
      success: function(user) {
        console.log(user);
        if (!user.existed()) {
          alert("User signed up and logged in through Facebook!");
        } else {
          alert("User logged in through Facebook!");
        }
        // go to home state:
        $rootScope.user = user;
        $rootScope.isLoggedIn = true;
        $state.go('app.home');
      },
      error: function(user, error) {
        alert("User cancelled the Facebook login or did not fully authorize.");
      }
    });
 
  } 
  //Native Login
  else {
    
    $cordovaFacebook.login(["public_profile", "email"]).then(function(success){
 
      console.log(success);
 
      //Need to convert expiresIn format from FB to date
      var expiration_date = new Date();
      expiration_date.setSeconds(expiration_date.getSeconds() + success.authResponse.expiresIn);
      expiration_date = expiration_date.toISOString();
 
      var facebookAuthData = {
        "id": success.authResponse.userID,
        "access_token": success.authResponse.accessToken,
        "expiration_date": expiration_date
      };
 
      Parse.FacebookUtils.logIn(facebookAuthData, {
        success: function(user) {
          console.log(user);
          if (!user.existed()) {
            alert("User signed up and logged in through Facebook!");
          } else {
            alert("User logged in through Facebook!");
          }
          // go to home state:
          $rootScope.user = user;
          $rootScope.isLoggedIn = true;
          $state.go('app.home');
        },
        error: function(user, error) {
          alert("User cancelled the Facebook login or did not fully authorize.");
        }
      });
 
    }, function(error){
      console.log(error);
    });
    
 
  }
 
};

https://github.com/webofbits/parkfinder