To make 'Due Date' mandatory in all the operations invoices

Currently, the Task & Alerts can be used to make 'Due Date' mandatory at the financial Invoice level only. We want to make the Due date mandatory at the operations invoice level and not at the finance invoice level.

When we set it up at the finance invoice level, the Ops invoice can be approved without the error popping up and it only appears at the posting of the invoice. At this time the invoice is already passed to the finance team. In order to enter the due date, finance has to reject the invoice, Ops has to re-do, and approve again which is double work.

We want to alert the Ops users to enter the due date in the Operations invoice when they save the ops invoice.