Hello, getting an error: Invalid or missing header on the code below- can anyone provide a working example of creating a purchase order in BOI? 

   using (var sySession = new MasSession(homePath))
            {
                sySession.InitSession(sessionLogon);

                CI.ColumnNames.Add("PO_PURCHASEORDER_BUS", new Dictionary<string, string> { { CI.NextNumberMethod, "nGetNextPurchaseOrderNo" }, { CI.HeaderKeyColumns, "PurchaseOrderNo$" } });
                using (var poEntry = sySession.CreateObject<ILineEntry>("PO_PurchaseOrder_bus", "PO_PurchaseOrder_ui", "P/O"))
                {

   var nextOrderNo = poEntry.GetNextDocumentNumber();

                    poEntry.SetKeyValue("PurchaseOrderNo", nextOrderNo);
                      poEntry.SetValue("PurchaseOrderDate", "20231101");
                      poEntry.SetValue("OrderType", "S");
                    poEntry.SetValue("APDivisionNo", "00");
                    poEntry.SetValue("VendorNo", "0008000");

                    poEntry.AddLine();

                    Trace.WriteLine(poEntry.Lines.GetKey());

                    poEntry.Lines.SetValue("ItemCode", "1001-HON-H252");
                    poEntry.Lines.SetValue("QuantityOrdered", 2);

                    poEntry.Lines.Write();
                    poEntry.Write();
                    
                    }
                    }