title: Pass field values from mvc application to the b2c sign up custom policy filelds
body: <p>I have email field in my MVC application. Once user given email-Id we are validating and have to pass the same email-id to the Azure B2C SignUp policy. For this I have created custom policy. Can any body help me how I can achieve this.</p>
  
  <p><img src="https://i.stack.imgur.com/9IqnW.png" alt="This is my mvc registration page filed"></p>
  
  <p><img src="https://i.stack.imgur.com/qFd1P.png" alt="This is my Azure B2C sign up page filed"></p>