I enabled two factor on many sites last year. Amazon is a bit late to the party, but they finally have two factor support. While they waited a long time, they did a good job with it.
Sign up was easy. They give you a choice of an authenticator app including scanning with your device to connect. Or you can use a mobile phone number for voice or text. Or you can use a landline with voice. You can set a second of these options as a backup. I like that there were choices.
You are also asked if the current device is trusted. Which is good as you don’t get prompted repeatedly from your main/home computer.
I also took this opportunity to check on twofactorauth.org to see if any other sites I use have added support. I was disappointed by how many banks don’t support two factor. I tweeted at four of them with the link on the page. (I don’t have accounts at all four).