You can make use of Auth0 progressive profiling and pre registration actions to fullfill this requirement by collecting the necessary details of the user (or) if this needs to be custom in your end, you can also implement self hosted embedded sign up page. Here is some additional information - Custom Signup
This topic seems related to our new EA feature, Forms for Actions, which rolled out of the beta stage on May 7th. Our Product team prepared the whole Documentation page with examples of Use cases. Forms for Actions. If you find yourself having questions regarding this new feature for the next two weeks, we are hosting an Ask Me Anything session. Our Product Expert will provide comprehensive written answers on May 21st from 8 AM to 10 AM PST.
Find out more about Forms for Actions and learn more about AMA.