OP metadata; must advertise registration_endpoint.
e.g. { redirect_uris, id_token_signed_response_alg, grant_types, ... }
Optionalopts: {OptionalallowInsecureRequests?: booleanOptionalfetch?: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>OptionalinitialAccessToken?: stringOptionaltimeoutMs?: number
Registers a client with an OpenID Provider (OpenID Connect Dynamic Client Registration 1.0, RFC 7591).