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Azure AD B2C user flows and user policies may be vastly complex. We cannot possibly cover all the options here, but will show some examples on what to configure.
It is recommended to use a standardized “User flow” if you can (see , but it’s possible for special requirement to configure custom policies (see https://learn.microsoft.com/en-us/azure/active-directory-b2c/custom-policy-overview ).

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Give your user flow an appropriate name, choose what MFA policy you like, and select user attributes and claims. Like you see, it’s not necessarily an option to select emails for a return claim at this pointSelect email addresses, given name, surname, display name and User’s Object ID to ensure that enough user data is provided to identify the user.

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3. Configure and change claims

After your new flow has been created, select it and go to Application claims to verify that all the claims were selected. Here, make sure that email addresses, Given name, suname, display name and User’s Object ID are selected.

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Configuring custom claims

Navigate to Azure AD B2c > User flows, and select the user flow you are using

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While under the user flow, go to Application claims in the left menu.

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Under user flow in Azure AD B2C, make sure name / display name is sent with claims:

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Custom policy to get additional claims

By default, a B2C user flow will not send the email attribute with the userinfo endpoint, or any data in the userinfo endpoint. To do this, you will have to configure a custom user policy. This requires some work.

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