// Menu
function custom_menu_shortcode( $atts ) {
    $atts = shortcode_atts(
        array(
            'name' => 'Menu Header',
        ),
        $atts
    );
 
    $menu = wp_nav_menu(
        array(
            'menu'            => $atts['name'],
            'container'       => 'nav',
            'container_class' => 'header-menu-custom',
            'echo'            => false,
            'depth'           => 0,
            'fallback_cb'     => false,
        )
    );
 
    return $menu ?: '';
}
add_shortcode( 'show_menu', 'custom_menu_shortcode' );