How to Hide the "Secure ur Admin" Admin Menu

function plt_hide_secure_your_admin_menus() {
	//Hide the "Settings → Secure ur Admin" menu.
	remove_submenu_page('options-general.php', 'secure-your-admin/inc/class_suadm.php');
}

add_action('admin_menu', 'plt_hide_secure_your_admin_menus', 11);

Where do I put this code?