using Aspose.CAD.Cloud.Sdk.Api;
using Aspose.CAD.Cloud.Sdk.Model.Requests;

var api = new CadApi("secret_key", "client_id");
var file = File.ReadAllBytes("FilePath");
var ms = new MemoryStream(file);
var request = new PutDrawingBmpRequest(ms);
var result = api.PutDrawingBmp(request);
using (var fileStream = File.Create("result.bmp")) 
{
  // Copy the stream to the file stream
  result.CopyTo(fileStream);
}