You are correct. There were buttons at the top of the payment section for flight credit and trip credit the last time I booked a flight a couple of weeks ago. Unfortunately, I ended getting an error message when I entered my ticket number for the flight credit option and had to put my reservation on hold and call reservations to complete the reservation. Reservations said the system did not know how to handle the extended expiration date, which was 12/31/21 at the time.