Editable reference number on Online Booking/Tendering

Summary:

We are trying to create editable reference number in online tendering screen with the goal to register license/registration plate, equipment and so on. We have created a new manager layout, adding the editable option but since no save button is displayed in the grid is not possible for servprov or even for Admin role, to any add any refnum.

Can you guide us to determine what is missing? We have found that there is a property which force refnum insertion as mandatory field in this screen so our assumption is that this feature is possible.

Thanks in advance for any help.