Autosourcing to update the existing PO

Hello Team,

We are using Auto-sourcing to select a supplier during the Back-to-Back PO autocreation process as below

1. Have ASL, Sourcing Rules and BPAs set up with the Autosourcing enabled in the instance

2. Create an SO for an ATO-Buy-Item and progress it till you get data in po_requisition_lines_all

3. Run Requisition Import

4. You will get a External Requisition and Approved PO

Now I want to add another line to the existing SO and want this SO line create another supply line in the existing PO itself. Do you know if there is any standard functionality to acheive this?