Fiscal Flow Drop Shipment Sales without OM

Hello,

The client is trying to receive two fiscal documents: one for Drop Shipment Sales and the other for Drop Shipment Remittance. However, they are using just one PO and have attached the first FD to this PO, which resulted in the status being marked as "Completed Prevalidation." When they try to receive the second FD, they are unable to do so because the PO has already been captured. They do not have OM.

What procedure should the client follow to correctly execute this process?