Optional
expOptional expiration timestamp (Unix timestamp).
Issuer URL identifying the organization.
Not before timestamp (Unix timestamp).
The verifiable credential content.
The credential subject containing FHIR data.
The FHIR Bundle containing medical data.
FHIR version in semantic version format (e.g., '4.0.1').
Array of credential types, must include 'https://smarthealth.cards#health-card'.
JWT payload structure for SMART Health Cards.