To enhance the security of a web application having a user authentication workflow, we use a security method called 2FA. It is also known as Two Factor Authentication(type of Multi-Factor Authentication). In this blog post, we will see how to implement email-based 2FA in ActiveAdmin auth of a Ruby on Rails application. In the email-based 2FA approach, when logging in with an email and password, an OTP will be sent on a registered email address. Upon entering the OTP, it will successfully authenticate and the session will be started. Also, we will see the following additional functionality and customizations