this my code and it add my primary-menu to WordPress so what I have to do that sub append to this menu
<?PHP
$default = array(
'container' => false,
'theme_location' => 'primary-menu',
'menu_class' => 'nav navbar-nav navbar-right'
);
wp_nav_menu($default);`enter code here`
?>
Read more here: How to add sub menu classes on wordpress theme development