Please follow below steps to register for OTP (Two factor authenticator).

For Android phone / tabs users

1. Go to Play Store or use the link Authenticator - Apps on Google Play
2. Search for Authenticator
3. Click on Install
4. After installation, open the authenticator app and select Add a new account.
5. Use the authenticator app to scan the QR barcode that's displayed on the screen.

For iPhone/iPad users

1. Go to App Store or use the link Authenticator on the App Store (apple.com)
2. Search for Authenticator
3. Click on Install
4. After installation, open the authenticator app and select Add a new account.
5. Use the authenticator app to scan the QR barcode that's displayed on the screen.