If you have notified the IBAN by 28th February 2019, remember that the first scholarship will be disbursed in April 2019.
 

Further payments are planned in conjunction with the disbursement of the second installments.  

Payment of the scholarship, what does it mean?

The deed with which EDISU orders the payment is intended.
Instead, the actual availability of the sum on your current account or on your card occurs in the following month, with variable timing in relation to the banking times of the credit institutions.  

If I don't communicate the IBAN within 31th DECEMBER 2020?

The scholarship will no longer be payable.