Return filing deadlines under GSTR-3B require electronic submission by the prescribed monthly due date and payment via electronic ledgers. Requires that FORM GSTR-3B returns for the quarter be furnished electronically through the common portal by the prescribed monthly due date, and directs registered persons to discharge tax, interest, penalty, fees or other amounts declared in the return by debiting the electronic cash ledger or electronic credit ledger, as applicable, no later than the last date for furnishing the return.