  
  Channel = "C070VPMKN8J";
  Block = OPI_Slack.GenerateImageBlock("https://opi.neocities.org/test_data/picture.jpg", "Image");
  
  Response = OPI_Slack.SendEphemeralMessage(Token, Channel,, User, Block); //Map
  Response = OPI_Tools.JSONString(Response); //JSON string
