iTextSharp PDF Save to Disk and Download option in ASP.Net C#

Hi Guy I have a problem saving the converted image(.jpg or .png) to PDF to a path, I have the following code that works great displaying the converted image to PDF in browser but when I try to save it to a path I get blank PDF here it my code, I am using .NET Framework 4.6.1 and iTextSharp.

default.aspx.cs

using System; using System.Collections.Generic; using System.Drawing; using System.IO; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using iTextSharp; using iTextSharp.text; using iTextSharp.text.pdf; using iTextSharp.xmp.impl;

//- HOW TO: var MyImage = Server.MapPath("~/media/sample.jpg"); Netstair.iTextShapHelper.ImageToPDF(MyImage,true,"~/export/");

public static void ImageToPDF(string uploadfilePath,bool saveToPath=false,string pathToSave="")
        {
            var _pdfiLename = "ConvertedIamge.pdf"; 
            var _pdfilePath;
            var _pdfileMedia;
            if (saveToPath==true)
            {
                _pdfilePath = HttpContext.Current.Server.MapPath(pathToSave);
                _pdfileMedia = _pdfilePath + _pdfiLename;
            }
            using (Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 10f))
            {               
                PdfWriter writer = PdfWriter.GetInstance(pdfDoc, HttpContext.Current.Response.OutputStream);
                pdfDoc.Open();

                //Add the Image file to the PDF document object.
                iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(uploadfilePath);
                //bytes = ImageToBytes(img);                
                pdfDoc.Add(img);
                pdfDoc.Close();
                
                // var outpuStreamem = HttpContext.Current.Response.OutputStream;
                if (saveToPath == true)                
                {
                     //- Save Converted Image to PDF to the passed path here
                  
                }
                else
                {
                    //- This works 100% fine, once the image converted to PDF it shows it on the browser as file downloaded
                    HttpContext.Current.Response.ContentType = "application/pdf";
                    HttpContext.Current.Response.AddHeader("content-disposition", "attachment;filename=" + _pdfiLename);
                    HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache);
                    HttpContext.Current.Response.Write(pdfDoc);
                    HttpContext.Current.Response.End();
                }
            }
        }

TIA