You will need to set your barcode label type as "Code 128" at Settings > Other > Labels.
A barcode representing the order ID can be added to invoice and goods out note templates by adding _barcode_ widget. Scanning this will let you identify the document, perhaps using our API.
Goods Out Note barcodes
When using Brightpearl WMS, add the _gnShortBarcode_ widget to your Goods Out Note template to enable scanning of the GON into WMS, or into carrier platforms like ShipStation.
You can also show a barcode for each item in the product table on a goods-out note. You will need to configure custom columns on the goods-out template by including the _productTable_ widget with the column code "barcode" to display it inline with it.