Create a new auth_link object by making a POST request to the auth_link endpoint. The new auth_link will effectively delete previous auth-links for that User/applicant, rendering the previous URL(s) invalid. The 'mobile' attribute is optional. If it is specified this number will take preference over the User object mobile number for 2FA SMS verification.
Returns a created auth_link resource, if the operation succeeded. Returns an error if the post failed (e.g. not supplying required properties).