Hi,
The product variant is already mentioned in the name column of the products listing of the order.
If you cannot differentiate the variant being purchased, it's likely that you set the same "name" in all the variants of the product.
So you would have to modify that, not the shipping invoice.
The shipping method is also displayed by default thanks to the code
<?php
if(!empty($this->shipping)) {
echo '<p class="hikashpo_order_shipping_method">'.JText::_('HIKASHOP_SHIPPING_METHOD').' : ';
if(is_string($this->order->order_shipping_method))
echo $this->shipping->getName($this->order->order_shipping_method, $this->order->order_shipping_id);
else
echo implode(', ', $this->order->order_shipping_method);
echo '</p>';
}
?>
in the order / invoice.php view file. So I don't see why you wouldn't already have it.
Thus, I'm not sure we're talking about the same thing at the same place.
I would recommend you provide more details on the situation.