BetaOptional BetacallCustom headers sent in the call setup as SVAML extra info. At most 16 headers; each key must be 1-255 characters, and each value at most 255 characters.
Optional BetaenableWhether speech can interrupt text-to-speech playback.
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.
BetasttBCP-47 language tag used for speech-to-text transcription, for example en-US.
See https://developers.sinch.com/docs/voice/api-reference/voice-locales for available locales.
BetattsVoice used when synthesizing speech, for example Emma.
See https://developers.sinch.com/docs/voice/api-reference/voice-locales for available voices.
Options for dialing a Voice Relay destination through the Sinch Voice V2 platform.