Many websites now offer 2FA or “two-factor authentication” which helps secure access to a website, such as Amazon, by either sending a SMS to your cell/mobile phone, or allowing you to use an Authentication application. When 2FA is enabled on the website, you will be asked for the 6 digit code generated by the Autentication app.
2FA adds another layer of security on top of the normal credential requirement, such as your username and password.
To set up the 2FA for a website, I recommend doing it on a computer rather than a phone, as it makes it easier to see what is going on rather than having to switch between apps on a cell phone.
Personally I use both the Google and Microsoft Authenticator apps on my cell phone.
To begin the process, I recommend installing both apps on your phone for redundancy, in addition to having another phone at hand when you add the website to the authenticator apps.
To help you regain access to the website in question, in case you lose your phone, or it gets damaged etc, when you are presented with the QR code by the website, which you use to add the website to the Authenticator app, scan the QR code into BOTH of the authenticator apps on your phone.
While the QR code is still on the computer screen, use another phone to also capture the QR code to the Authenticator app on that phone.
Also, take a screen shot of the QR code, which you can use to add to another Authentication app in the future.
Finally, if you are presented with back up codes, in order to access your account in case the 2FA stops working, avail yourself of the opportunity and print the codes. Put them in a safe place in case you are ever locked out of your account.