Is there a way to update Need-by Date or Promised Date by POPurchaseOrderImportTemplate?

Hello,

I have a question for updating Purchase order by FBDI.

In the PO FBDI, sheet PO_LINES_INTERFACE, we only could choose ADD in Action column.

And also we need to fill PO_LINES_INTERFACE data for updating PO_LINE_LOCATIONS_INTERFACE data.

So does that mean, I can't make updates to existing lines?

If you know, I need your help.