Hi All,

I have configured AD B2C on dynamics portals

By default when user signs up if there is an exisiting contact with email the portal b2c user will be assosiated

But my requirment is to map with a unique auto number generated in CRM and user inputs that number on the sign up form. 

Email is not a unique value in our system so wanted to see if we can leverage any custom attribute to map the registrerd user

Thanks in advance