How to buy on Amazon using bitcoin?

I'm curious about something, could you possibly enlighten me? I've been hearing a lot about the use of bitcoin for online purchases, but I'm still a bit hazy on the details. Could you possibly explain to me how exactly one would go about buying items on Amazon using bitcoin? Is there a special process involved? Do I need to convert it to another form of payment first? I'm quite fascinated by the idea of using cryptocurrency for everyday transactions and I'd love to learn more. Would you be able to shed some light on this for me?