订购Itemmeta woocommerce

Question

I must to edit a product name in woocommerce when in the product was add ('_aggiunte), _aggiunte is a custom field of woocommerce_order_itemmeta tabs.

I try with this code but don't word.

function woocommerce_new_order_item_add_aggiunte($item_id, $item, $order_id) {
$item_type = $item->get_type();
   $order= wc_get_order($order_id);
    // We only want product order type
    if ($item_type == 'line_item') {
        $product = wc_get_product($item->get_product_id());   
        $new_name=get_post_meta($product_id, '_tmcartepo_data', true);
        $item->set_name($new_name);
        $item->save();  
    }
}

thanks. I want to show produtname-aggiunte.