Australia Post charges postage based on the parcels included in an Australia Post Order Summary Report, and despite not having a scannable barcode, this is your official Order Summary Report.
To generate your daily Order Summary, first click the Settings icon (the wrench icon).
Now click Open from the End of Day dropdown.
Find Australia Post and click Close Shipments for the desired day's parcels.
Click Close All or select the shipments you need to close and click Close Selected.
After your shipments are closed, you can print the Order Summary Report!
Pro tip: You can go to the Shipments page and locate the Forms column and all manifested Australia Post shipments will have a barcode icon.