To add your FSA/HSA card to your Amazon account, please do the following steps listed below.
Log into your Amazon Account.
In the upper left hand corner of your Amazon account, click on the menu.
Click on Account.
Scroll down and under the "Payments" heading, click on "Your Payments".
Click on Add a payment method.
Click on add a FSA or HSA card.
Fill out your card info, and don't forget to click on "Add your card".