In case you need to suspend payment of one or more installments of an already issued order, or simply decide on the due date at a later date, you will be able to set the due date as "to be defined." Navigate to Financial Management → Order Management and click the blue icon "Manage installments and payments" on the line of the enrollment order for which you intend to change the due date. From the next screen click the middle blue "Redetermine the definition of installments or apply a discount".
From the next screen, click the little clock symbol next to the expiration date, followed by the green icon in the center of the screen to save the operation.
Therefore, the installment will now be with a due date to be determined and thus will be found to be suspended until a new date is decided.