Add Extra functionality when login as super user login

[Rupam Hazra]

Hi,

I want to add extra validation on superuser login.Actually i want to modify the login process due to security prospect.

Step-1 : give username and password form and send a mail with otp

Step-2 : after that a form will open and put that otp to verify then it's going to dashboard page.

So, Please help me to do this.