"Feature depreciated"? so how do I change account creation details?

This feature was essential for our organization, it allowed us to customize and add fields for users during account creation. Is the feature just gone or has it been moved somewhere? we can't find it.
https://stackideas.com/docs/easysocial/administrators/hows-to/how-to-assign-custom-fields-into-mini-registration

Please assist. Thank you.