diyoz

I had already implement for multiple sku printing.

214             // support printing for multiple product sku
215             $order_meta['sku'] = '';
216             $items = $order->get_items();
217             foreach ($items as $item) {
218                 $product_qty = $item['qty'];
219                 $product_variation_id = $item['variation_id'];
220                 // Check if product has variation.
221                 if ($product_variation_id) {
222                     $product = new WC_Product($item['variation_id']);
223                 } else {
224                     $product = new WC_Product($item['product_id']);
225                 }
226                 $sku = $product->get_sku();
227                 $order_meta['sku'] = $order_meta['sku'] . $sku . ' * ' . $product_qty . ' + ';
228             }
229             $order_meta['sku'] = rtrim($order_meta['sku'], "+ ");