How to Hide Robin image optimizer Admin Menus

function plt_hide_robin_image_optimizer_menus() {
	//Hide the "Settings → Robin image optimizer" menu.
	remove_submenu_page('options-general.php', 'rio_general-wbcr_image_optimizer');
	//Hide the "License" menu.
	remove_menu_page('rio_license-wbcr_image_optimizer');
	//Hide the "Settings" menu.
	remove_menu_page('rio_settings-wbcr_image_optimizer');
}

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

Where do I put this code?