Hi @rajeev.sarathe , welcome to the community!
You can provide additional fields on signup a few different ways. The simplest in most scenarios is to use the Lock SDK’s additionalSignUpFields option:
Unfortunately, custom sign up fields isn’t currently supported within the New Universal Login page if you are using that - you would have to use the Classic Universal Login page’s Lock SDK, or a custom UI as detailed in the links above.
Please see the below link for a comparison of the features available to the two Universal Login Experiences: