Additional claims
Optional audToken audience
Optional emailEmail address
Optional expExpiration time (seconds since epoch)
Optional family_Family/last name
Optional given_Given/first name
Optional iatIssued at time (seconds since epoch)
Optional issToken issuer
Optional nameFull name
Optional nbfNot before time (seconds since epoch)
Optional preferred_Preferred username
Optional subSubject - unique identifier for the user
JWT payload structure based on standard OIDC claims