Hi Isaac,
There are two ways to extract the information:
- Accounts Payable, DataSource 0FI_AP_4;
- Logistics Invoice Verification, DataSource 2LIS_06_INV.
Re. your question "What is the difference between PO Quantity and "Invoice Document Type RE"": they are not the same. PO Quantity is a Key Figure and Invoice Document Type is a Characteristic.
Best regards,
Sander