Here is my code and it works (I used NuGet package Select.HtmlToPdf. Document.Save saves the PDF instead I would like the PDF open for user to review (instead of saving in computer)
    HtmlToPdf converter = new HtmlToPdf();
    // create a new pdf document converting an url
    PdfDocument doc = converter.ConvertUrl("www.cnn.com");
    // save pdf document
    doc.Save.(Response, false, "test.pdf");  // false: will not save the document
    // close pdf document
    doc.Close();