HS/HSN Code on packing-slip

Thanks for mentioning that again, @holle75!

I think we overlooked that part! I have updated the code snippet to make it compatible with variable products as well:

/**
 * WooCommerce PDF Invoices & Packing Slips:
 * Display HS/HSN Code after item meta (if not empty)
 */
add_action( 'wpo_wcpdf_after_item_meta', function( $document_type, $item, $order ) {
    if ( isset( $item['product'] ) && is_object( $item['product'] ) ) {
        $product = $item['product'];

        // If the product is variable, get the parent
        if ( $product->is_type( 'variation' ) ) {
            $parent_id = $product->get_parent_id();
            $product = wc_get_product( $parent_id );
        }

        // Get the product HS Code
        if ( $value = $product->get_meta( '_hs_code' ) ?: $product->get_meta( 'hs_code' ) ) {
            echo "<div class=\"hs-code\"><small>HS/HSN Code: {$value}</small></div>";
        }
    }
}, 10, 3 );

Let me know whether it worked, or you need more tweaks!