To make VolunteerHub as easy for volunteers as possible, there are several ways a user can sign in or create an account.
One of those methods is to utilize a social media account:
Should a user create their VolunteerHub account via one of the social media options above, they would have never created a username or password. Instead they'd be signing in with the credentials of their linked account.
This does not mean they wouldn't have filled out an application; they would still be required to provide answers to all user form questions marked as required (e.g., Date of Birth or Home Address).
If you rely on username as a unique, reportable field instead you can use 'User UID' within reports as every user has a unique value for this field.