Hi, I would like to know how can I implement a Two-factor authentication.

1. if user is successful logged in then a pin will be generated in mysql and in parallel sent via an api as a SMS
2. user is redirected to the PIN form. If the submitted pin matches the generated pin then the user will be considered as authenticated and will have access on the site.
   How can I do this, where can I start from?
   Than you!