title: Any way to provide default values for inputs in an Azure AD B2C custom policy?
body: <p>I am working on integrating Azure AD B2C into an existing shopping cart application, replacing an existing user identity solution.</p>
  <p>I have already created a custom policy to implement user registration / sign-up and integrated it into the normal account creation process. However, I am having a problem with integrating registration during the checkout process.</p>
  <p>With the old IDP, the checkout process first collects the user's name and email address. After that has been collected, the user is given the option to create an account with that information (if they are not already logged in). In order to avoid confusing double-entry of the email address, I would like to pass the email address that the user already entered to the B2C sign-up policy and have it fill in the email address input on the form.</p>
  <p>Is there any way to do this? I don't find anything like this being addressed in the B2C documentation.</p>