Yes, you can buy stuff on Amazon using
BTC. There is a wallet called Ipayyou (it is 2 years old age now) that allows you to buy on Amazon using your bitcoins. The wallet has a featured called Amazon Direct that lets you transfer any dollar amount of bitcoin to use for purchases on Amazon. I might be mistaken but I think this is the only way, for now, to buy things on amazon using bitcoins.
For more information check:https://bitcoinexchangeguide.com/ipayyou/
or visit :
https://wallet.ipayyou.io/I haven't used their service but it seems they hold private keys which is little bizarre for sites like that. It is interesting if it works as people are always buying things from amzon but I would suggest that if you're first time buyer, don't buy anything too expensive, buy something cheap to try it to see if it works and how smooth transaction goes before you buy anything expensive.