如何在wordpress中获取facebook用户名facebook所有插件

我在wordpress中使用facebook-all插件进行facebook登录，但它没有检索用户名，而是附加了名字和姓氏。如何获取确切的用户名？

$fbdata = facebookall_get_fbuserprofile_data($fbuser_info);
    if (!empty($fbdata['email']) AND !empty($fbdata['id'])) {
      // Filter username form data.
      if(!empty($fbdata['name'])) {
        $username = $fbdata['name'];
      }
      else if (!empty($fbdata['first_name']) && !empty($fbdata['last_name'])) {
        $username = $fbdata['first_name'].$fbdata['last_name'];
      }
      else {        $user_emailname = explode('@', $fbdata['email']);
        $username = $user_emailname[0];
      }