How to get Stream From LeadDocument

var createOptions = new CreateDocumentOptions();
LEADDocument leadDocument = DocumentFactory.Create(createOptions);
leadDocument.Name = "Virtual";

try
{
    // Add page 1 and 2 from a PDF file 
    LoadDocumentOptions loadOptions = new LoadDocumentOptions();

    foreach (var folderDocumentId in folderDocumentIds)
    {
        int folderId = folderDocumentId.Key;
        IEnumerable<int> documentIds = folderDocumentId.Value;

        var folder = ..Getting Folder Details...

        var flrnostr = xyz;

        foreach (var documentId in documentIds)
        {
            var document = ...getting document details

           // Get File Binary

            var leadDocumentLoadOptions = new LoadDocumentOptions();
            // load document stream
            var documentBytes = (await fileService.GetFileBytesAsync(document.path)).Item1.ToArray();
            using var stream = new MemoryStream(documentBytes);
            
            LEADDocument childDocument = DocumentFactory.LoadFromStream(stream, loadOptions);
            leadDocument.Pages.AddRange(childDocument.Pages);
        }
    }

    // Tell the parent document to dispose any child documents when the parent is disposed 
    leadDocument.AutoDisposeDocuments = true;

    // Show the info of this document, should say 5 pages 
    //Console.WriteLine("Original document information");

    // Now save, the parent document into the cache 
    //leadDocument.SaveToCache();

    // And tell all documents to not delete themselves from the cache 
    leadDocument.AutoDeleteFromCache = true;

    // Save the ID so we can load it 
    //documentId = leadDocument.DocumentId;

    return File(leadDocument.Documents.First().GetDocumentStream(), "application /octet-stream"); // Here I get the error cannot access the closed stream
}
finally
{
    if (leadDocument != null)
        leadDocument.Dispose();
}

static MemoryStream Test(string folder)
{
     // Where you manage all the streams used for disposal
     List<MemoryStream> streams = new List<MemoryStream>();
     var outputStream = new MemoryStream();
     var createOptions = new CreateDocumentOptions();
     LEADDocument leadDocument = DocumentFactory.Create(createOptions);
     leadDocument.AutoDisposeDocuments = true;
     leadDocument.AutoDeleteFromCache = true;
     leadDocument.Name = "Virtual";
     var files = Directory.GetFiles(folder);
     foreach (var file in files)
     {
          var documentBytes = File.ReadAllBytes(file);
          MemoryStream ms = new MemoryStream(documentBytes);
          streams.Add(ms);
          LEADDocument childDocument = DocumentFactory.LoadFromStream(ms, new LoadDocumentOptions());
          leadDocument.Pages.AddRange(childDocument.Pages);
      }
      // Finalized the new document
      DocumentConverter documentConverter = new DocumentConverter();
      var jobData = new DocumentConverterJobData
      {
           Document = leadDocument,
           // This is the stream you want to send back to the browser
           OutputDocumentStream = outputStream,
           DocumentFormat = DocumentFormat.Pdf,
       };
       var job = documentConverter.Jobs.CreateJob(jobData);
       documentConverter.Jobs.RunJob(job);
       foreach (var error in job.Errors)
           Console.WriteLine($"There was an error:{error.Error}");
       // Return the stream of the new document
       return outputStream;
}
// Dispose of the streams
finally
{
       foreach (var stream in streams)
       stream?.Dispose();
}