public async Task <IActionResult> GetPreview(Guid sourceId, string text, Language language, Speaker speaker, Emotion emotion, decimal speed, int offset = 0)
{
var headers = await _sourceService.GetHeaders(sourceId);
var content = await _sourceService.GetContent(sourceId, 1, offset);
var finalText = _textConverter.GenerateResultingText(headers, content.Items.FirstOrDefault(), text);
var voiceFile = await _voiceService.GenerateAudio(finalText, language, speaker, emotion, speed);
return(File(voiceFile.Value, "audio/mpeg", voiceFile.Key));
}