How to stop auto approval of Purchase order created from punchout requisition

Summary:

How to stop auto approval of Purchase orders created from punchout requisition

Content (required):

The client wanted to stop purchase orders from getting approved from a punchout requisition, which should be in Incomplete status.

So that buyer will review and make the required changes (if any) and submit them for approval.

Also, another requirement is - Negotiated Checkbox is enabled for Enter Requisition Line page, so the user will enable Negotiated Checkbox and create a requisition (Destination Type = expense) there is no Agreement attached to it.

For this case also, PO will be auto crated and stop getting approved, How we can achieve this?