[SOLVED] Retrieving invoices not booked yet

I am trying to retrieve all supplier invoices which have not been booked yet. I am using the logic:

ICurrentSupplierInvoice[] invoices = _session.CurrentSupplierInvoice.GetAll();

I cannot figure out why it does not return with any records. Do you have an idea what I am doing wrong?

Below you find a screenshot from the system. I expected to get the record seen on the list extracted.

I hope that you can help me out.

Kind regards,
Mihael Petri