How to prevent buyer from manually changing the quantity or amount on PO with a backing requisition
We have the following scenario:
Requisition created for quantity = 2 and amount = 50. The requisition gets approved.
Buyer while converting into a PO (process requisition lines) manually changes the quantity to 5,amount = 10, charge account and creates a PO and PO gets auto approved .
In this case the approval was obtained for lesser qty.
Is there a way to prevent this ? whether approval can be triggered when there is a change from PR to PO.
Also in this case the requester is the buyer.
All inputs are appreciated.