public ActionResult <string> Post([FromBody] PdfDocument document) { PdfOutput pdfOutput = new PdfOutput() { OutputStream = new MemoryStream() }; PdfConvert.ConvertHtmlToPdf(document.Convert(), pdfOutput); var bytes = ((MemoryStream)pdfOutput.OutputStream).ToArray(); if (bytes != null) { pdfOutput.OutputStream.Close(); return(Ok(Convert.ToBase64String(bytes))); } return(StatusCode(404)); }