Split the set-up for the field Ext. Doc. No. Mandatory.

The request is to have the option to leave the field as non-mandatory when creating a purchase order but leave the field as mandatory when receiving/entering the invoice because when we’re entering the PO, we don’t have the external document yet. So while when we receive the purchase invoice, we’ll have the document number, and it is sensitive information for tracking payments.
To solve this, we would need to have two settings separately for PO and PI.