How to Hide the "Page Link Generator Options" Admin Menu

function plt_hide_page_link_generator_menus() {
	//Hide the "Settings → Page Link Generator Options" menu.
	remove_submenu_page('options-general.php', 'plg-options');
}

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

Where do I put this code?