When ERP is not integrated with HotWax Pre-Order Management System, how can we add new pre-order items to an existing purchase order?
you have 2 options. You can manually update the PO from the HotWax Commerce view PO screen using the add item function. Alternatively you can also export the PO from your ERP and upload it to HotWax Commerce using the Import App. If it has the same PO id as the existing PO in HotWax, it should update it with the new changes.
For smaller changes like adding a few items, I’d say using the add or edit item functions is best