Using Register with Facebook

I've set up register with Facebook, and i've linked a profile type to be used during Facebook registration.The site now allows to register using Facebook id.

But the issue is that there are custom fields (Mandatory) in the profile type, which are not shown if a users uses registers via Facebook.

The current flow of Facebook registration is:
Click on Login with Facebook takes to .../community/registration/oauth/facebook, which asks to click on "Create my account" button
Which takes to "Select Profile type" (Although i've defined a profile type in registrations settings)
When clicking on profile type, it takes me to "set password, import avatar & cover" and complete registration.

There is no option for the facebook user to fill in the mandatory custom fields which are defined in the profile type.

I might be missing on some settings, can you please guide me on this.

regards