I am trying to add a user to a group. I can run this PHP code without any errors, but the user group is still not changed.

```
<?php

define('_JEXEC', 1);
define('JPATH_BASE', realpath(dirname(__FILE__)));
require_once ( JPATH_BASE .'/includes/defines.php' );
require_once ( JPATH_BASE .'/includes/framework.php' );
require_once ( JPATH_BASE .'/libraries/joomla/factory.php' );

$userId = 358;
$groupId = 11;

echo JUserHelper::addUserToGroup($userId, $groupId);

?>

```