OptionalclientPublicKeySetUrl?: stringIf provided overrides the clientPublicKeySetUrl from the authorize
options (if any). Used for jku token header in case of asymmetric auth.
The code URL parameter received from the auth redirect
OptionalprivateKey?: JWK | { alg: "ES384" | "RS384"; key: CryptoKey; kid: string }Can be a private JWK, or an object with alg, kid and key properties,
where key is an un-extractable private CryptoKey object.
The app state
Builds the token request options. Does not make the request, just creates it's configuration and returns it in a Promise.