I prefer to wait for amazon's announcement that telling to the public that they will accept crypto as the payment because I am afraid that if we use a browser extension, it could attract hackers to find the hole. That can make us get trouble because they can see and steal the coins from that hole. I prefer to use another wallet that can give a chance to pay directly through the amazon website than to use the browser extension. It looks safe, but we don't know if they can always secure the file from the hacker.