https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.Dialogflow.Cx.V3/latest/Google.Cloud.Dialogflow.Cx.V3.ResponseMessage.Types.OutputAudioText.SourceOneofCase
Dialogflow v3 API - Enum ResponseMessage.Types.OutputAudioText.SourceOneofCase (3.1.0) | .NET...