Requesting user's email address


I am preparing an android App and want to request a user to share his/her email address. I have used Twitter kit framework for authenticating user. That part of my App has been done successfully. Now, I want to request user email. I have referred to your documentation telling me to visit a form. In that form, I couldn’t found an option for requesting a user’s email.
So, I need some guidance for the process for achieving this. Waiting for your response.
Thanks in Advance.