Handling Declined Authorization Permissions
When your users are authorizing your application, some providers (such as Facebook) allow the user to select the attributes they wish to share.
By default, this selection is made only when the user authorizes the app for the first time. If your user chooses to not allow certain attributes (such as their email) that are required by your application, the user will not be able to access your application.
In such instances, your user will need to be re-prompted to grant permission to the required attribute(s) to login.
How to re-prompt for permissions
Alternatively, you can set this with Auth0.js using prompt: 'consent'.