Only fields with orange surround are compulsory.
Raise a new PO at New PO Request (to save time, the free trial is released with one supplier, two items, & two ledgers, all of which can be deleted)
Receive the goods or service ordered under the PO at Receive.
Close the PO in My POs and All POs.
Upload the invoice for payment
Match the PO to the invoice.
Authorise payment of the invoice.