const htmlOutputOptions = new PDFNet.Convert.HTMLOutputOptions();
// Set e_reflow_paragraphs content reflow setting
htmlOutputOptions.setContentReflowSetting(PDFNet.Convert.HTMLOutputOptions.ContentReflowSetting.e_reflow_paragraphs);
// Optionally set to flow paragraphs across the entire browser window.
htmlOutputOptions.setNoPageWidth(true);
// Convert PDF document to HTML with reflow paragraphs option turned on
// But requires the PDF2HtmlReflowParagraphsModule
await PDFNet.Convert.fileToHtml(filename, output_filename, htmlOutputOptions);