how to make the requester field on procurement my receipts page not required (Direct POs)?

For our client's business process, we are looking for a solution to make it so it isn't required for the requester on the PO to be a field mandatory to properly populate receipts in the my receipts page under procurement. This is will be especially impact users who are populating a receipt from direct purchase orders. In the case of a direct purchase order, it cannot always be expected that a user will remember to populate the requester field at the line level to allow for receiving in self-service receiving in the procurement module. For the purpose of searching