How to Hide PickPlugins Download Monitor for WooCommerce Admin Menus

function plt_hide_woo_download_monitor_menus() {
	//Hide the "WC Download Monitor" menu.
	remove_menu_page('wdm-downloads');
	//Hide the "WC Download Monitor → WC Download Monitor" menu.
	remove_submenu_page('wdm-downloads', 'wdm-downloads');
	//Hide the "WC Download Monitor → Settings" menu.
	remove_submenu_page('wdm-downloads', 'wdm-settings');
}

add_action('admin_menu', 'plt_hide_woo_download_monitor_menus', 13);

Where do I put this code?