yes that is what i mean here as you can see from my demo here
demo.joomlaaa.com/index.php?option=com_comprofiler&task=registers
you will see that there is no username field in the form so user will put his email only and his username will be the same like email that what this plugin do

this plugin just uses Javascript to change the form fields on registration. I dont think this is the best way to do it as javascript is not the best, some people may not have javascript. I think it should be PHP to change the POST variables after submit, and just turn off the username field in Admin. Also, this does not turn off the Username field in "Forgot Password" page, which should be done in combination with any plugin that removes the username.

So I have decided not to use this plugin and hack the CB core files.

In my opinion CB needs to change to have the Username as optional so we are not left with hacking.

i have tried to unpublished or hide username field but that will not work without hacking to core files as community builder validation script will prevent submitting of form
and it must done with java that is the best way if we want to not hack cb files
please see it here

demo.joomlaaa.com/index.php?option=com_comprofiler&task=registers

I have hidden the username field, made the email field the login field, but the problem is that in the username field Firstname and Lastname is saved.

So if there are two Peter Pan's then the second Peter Pan will not be able to register.

Is there another setting I need to change?