Two Factor Authentication - How? when? and where?

Why it is required?

The most common practice is to add user's name and password to validate user. This legacy authentication and authorization alone wont go with the sensitive future apps. Subsequently, their is now way to verify that the end user is our real subscriber and if the user is bond to his offered services.
However, complex password may give security from the user side but it has its own flaws, like Its harder to remember. Well the answer is simple 2FA authentication is the ultimate option.

How does it work?

During user registration send a rondom code (Passcode) will be provide via a sms or email or even both.
The Subscriber will receive the OTP (one time password) add it back to the app.
Hence the user and device both can be verified.