How to Hide the "OpenWidget" Admin Menu

function plt_hide_free_customer_service_tools_by_openwidget_menus() {
	//Hide the "OpenWidget" menu.
	remove_menu_page('openwidget');
}

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

Where do I put this code?