Beginning in version 1.65.0, FusionAuth offers Complete Registration. Full docs here.

How this would work:

enable a registration form for the application your users are logging into select certain attributes as required. If you are using a basic form, you could select 'birth date'. If you are using an advanced form, you can select whatever profile attributes you need set the Registration mode to Complete registration. This setting means that users cannot self-register, but can complete missing information from an existing registration. save the application

Now, your admin user can create a user with a minimal amount of data (perhaps just an email address).

The user will, at first login, be prompted to fill out their profile data, including all fields you've marked required.

This is not full progressive registration, but can be useful in certain circumstances.

Hey @dan,

I guess I need something similar for user.data.username. I need to define a rule on this custom user data to be unique in my app or tenant. As of now I really do not care about tenant or app since I only have one tenant and one app in my FusionAuth.

So I've asked this Q&A and I need to enforce uniqueness for this data. But dunno how to do it. Any suggestion?