Receiving e-invoices from an Polish company
The user process for receiving an e-invoice doesn't change from what's described in:
How to use ExFlow e-Invoicing
The added value of using ExFlow e-Invoicing along ExFlow AP is that the KSeF number that is embeded in the incoming invoice (as approved by KSeF) is extracted and stored in the UUID field and will be stored in the standard D365 tables.
Note that due to some architectural constraints in D365 Finance, ExFlow AP must be configured as Direct Posting for the KSeF number to be stored in the correct table.