Hi @TosohLBlum,

I’m afraid the Logical Unit ‘IncomingInvoice’ which is associated with the window Supplier Invoices Analysis cannot be extended to support custom objects. If you query the Excluded Logical Units window, you can see that it is excluded and cannot be extended.

I was actually able to do this.  I couldn’t find the Excluded Logical Units window, but while looking for it, I found Solution Manager/System Information and Utilities/Logical Units/Logical Units.  From this window I was able to activate the Rowkey.  Then when I returned to the Supplier Invoices Analysis window I was able to add the custom field.