Read Fillable PDF form fields in ASP.NET

I have a fillable PDF form created using Adobe Acrobat DC and I want to submit this form to a URL: http://localhost:49168/WebForm1.aspx.

I am using Aspose.Pdf library to read the PDF file on my code but whenever I am trying to read the file it throws an exception: "Incorrect file format". Can anybody help/guide me how to read the fields from this form.

Below is code I am trying to use:

protected void Page_Load(object sender, EventArgs e)
    {
        string pdftype = Request.ContentType;
        int pdfocument = Request.ContentLength;
        try
        {
            byte[] pdf = new byte[pdfocument];
            Stream stream = new MemoryStream(pdf);
            Aspose.Pdf.Facades.Form form = new Aspose.Pdf.Facades.Form(stream);

         //   HttpContext.Request.InputStream.Read(pdf, 0, pdfocument);
            Document doc = new Document(stream);


        }
        catch (Exception ex)
        {
        } 

    }

I resolved the issue with using HTML export format instead of FDF format and read the values using Form collection.