OptionalcreateOptionalIdempotency-Client-generated idempotency key to safely retry requests. The server uses this key to recognize retries of the same request. If a request with the same key is received within 10 minutes, the server returns the cached response from the original request. Using a random UUID (v4) is strongly recommended. If omitted, the SDK generates a UUID v4.
OptionalserviceThe ID of the service. If omitted, the project's default service is used.
Request payload to initiate a single outbound call.