BetaOptional BetacliCaller identifier, also called "Calling Line Identification" in the context
of PSTN, presented for this dial. When omitted, the client-level identifier
passed to SinchClientBuilder.callerIdentifier is used.
Optional BetaserviceIdentifier of a Sinch Voice V2 Service whose configuration (webhooks, signing credentials, call behaviours) governs the dial. When omitted, the project's default Service is used.
Options for dialing a phone number through the Sinch Voice V2 platform.