Customization Of Login

I created user with email, and password=12345

when I login through this email id and password, I loged in successfully but
If I want to login using email id = test and password=12345.

How do I Achieve this. Please assiste me.

Thank you

Currently the user id is the email id. Not customizable out of the box.

Login with existing email id and add user name as test and enable option in system settings.
You can login with either User name or Mobile No. or email Id.