I remember that when I called to schedule my date, the person told me that I could use visa,master card or American Express. I think it's maybe the same in internet.
Doesn't your debit card belong to Visa? if it does, the sign " Visa " can be seen on the card.
Anyway, I remember the person asked me whether it's debit card or credit card. So I think debit card can be used to pay the fee, too. Don't worry, you can do step by step according to the illustration.