YITH WooCommerce PDF Invoices & Packing Slips allows you to automatically generate the invoice in PDF format for each registered order in your shop.
The features of this plugin integrate with those of YITH WooCommerce Order & Shipment Tracking which will allow entering tracking data in the packing slips generated with YITH WooCommerce PDF Invoices & Packing Slips.
After activating both plugins, you will be able to enable the option Show in packing slip, thanks to which the order tracking data will be automatically inserted in the generated document.
For further details about YITH WooCommerce Order & Shipment Tracking, please refer to the official documentation.