Before you connect Payhawk to DATEV Unternehmen Online (DUO), you need to define the permissions in your accounting software for performing the data fetching between the two systems.
To configure the permissions for connecting Payhawk with DUO:
Log in to your DUO account.
Go to Documents > Settings.
In the dialog that opens, click on Bearbeitungsform.
Click on Bearbeitungsform ändern.
For the Lieferantenrechnungen and Kundenrechnungen sections, select Erweitert.
From the respective Rechnungsordner field, select Ware, Leistung.
Click on Weiter to confirm your settings.
On the Fertig stellen screen, review the changes and click on Weiter. As a result, on the Bearbeitungsform settings page, you can see the two settings with the Erweitert option.