speak method
Speaks text using a text-to-speech engine.
utterance The text to speak, either plain text or a complete,
well-formed SSML document. Speech engines that do not support SSML will
strip away the tags and speak the text. The maximum length of the text
is 32,768 characters.
options The speech options.
returns Called right away, before speech finishes. Check
runtime.lastError to make sure there were no errors. Use
options.onEvent to get more detailed feedback.
Implementation
Future<void> speak(
  String utterance,
  TtsOptions? options,
) async {
  await promiseToFuture<void>($js.chrome.tts.speak(
    utterance,
    options?.toJS,
  ));
}