Customize "Change Password" UI for guest invitation with additional fields

Hey folks, I have an application in which a user can be added to the system from multiple sources which includes direct signup of the user using the normal signup process. In addition to this, admin can add few users to the system to which our backend should send an invitation link to the email registered and the form on redirection should be pre-filled with the values. I was looking into Send Email Invitations for Application Signup. From what I have understood till now from the docs, unless the user logs in, we cannot access the user.metadata object in the forms. So, I feel we cannot show them the fields with pre-filled values. As we can customize the UI I was thinking to add additional fields to this form. Is it possible to this? If yes, how can we store these additional details in the Auth0 database?