Update file Download Count in ASP.Net

Maybe IHttpHandler or not. Please how to get if users successfully downloaded server documents and then increase the Total Download based on the Download Button Click.

<asp:Button ID="AS" runat="server" Text="DownLoad Here" CssClass="mainBtn" OnClientClick="CallHandler();" />

public class DownloadHandler : IHttpHandler
{
  public void ProcessRequest(HttpContext context)
  {
     
    string fileName = 
    context.Request.QueryString["filename"].ToString();
    
    string fileWithPath = Server.MapPath("~/File/" + fileName);
    
    
   FileInfo file = new System.IO.FileInfo(fileWithPath);
   if (file.Exists)
   {
      try
     {
            //SQL 
        INSERT INTO file (count) VALUES(
         SELECT TOP 1 (count + 1) FROM file ORDER BY count DESC)
         
         SET @DCount = SELECT TOP 1 (count + 1) FROM file ORDER BY count DESC)
        
         // set count to Label
         lblCount.Text = @DCount;
     }
     catch (Exception)
     {
        //handle
     } 
  
     //return the file
     context.Response.Clear();
     context.Response.AddHeader("Content-Disposition",  "attachment; filename=" + file.Name);
     context.Response.AddHeader("Content-Length", file.Length.ToString());
     context.Response.ContentType = "application/octet-stream";
     context.Response.WriteFile(file.FullName);
     context.ApplicationInstance.CompleteRequest();
     context.Response.End();
     
    }
  }
  
  public bool IsReusable
  {
  get { return true; }
  }
}

function CallHandler() 
{
    $.ajax({
        url: "DownloadHandler.ashx",
        contentType: "application/json; charset=utf-8",
        dataType: "json",    
        data:
        { 
            filename: 'read.pdf'
        },    
        responseType: "json",
        success: OnComplete,
        error: OnFail
    });
    return false;

}   //Function CallHandler ends here

function OnComplete(response) {
    debugger;
    alert('download completed');
    //increase label count
}

function OnFail(response) {
    alert('Request Failed');
}

Thanks