Adding NO PART REQ line to a 2-DIRECT DELIVERY Purch Req.

Hello - I added a non-inventory to a sales order and released the sales order. The Purchase Requisition was created. I need to add NO PART REQUISITION lines to the req before I convert the req to a PO. I received an error message that the line could not be inserted in ORDER CODE 2 - DIRECT DELIVERY.

I then tried creating another req and added all the NO PART REQ lines, but I could not add the req to the first PO.

Any ideas?