question

Yes, you can generate PDF from the data you have. iTextsharp is a pdf library that will help you generate pdf document from code. I published an article about generating the pdf from itextsharp, you can read this below.

https://weblogs.asp.net/sreejukg/create-pdf-document-using-itextsharp-in-asp-net-4-0-and-memorymappedfile

hope this helps

Thanks but this is not what I am looking for; I already know how to export GridView data to PDF.
My question was "how to export the entire form that include 'captions' and 'user inputs' to PDF"

The article was about how to use iTextsharp to generate pdf. it is possible to generate form. Refer the following sample.

https://kb.itextpdf.com/home/it7kb/ebooks/itext-7-converting-html-to-pdf-with-pdfhtml/chapter-7-frequently-asked-questions-about-pdfhtml/can-i-convert-an-html-form-to-a-pdf

I've looked at that example and still not been able to see how it would convert asp page to pdf.
Also, I did have all references to iTextSharp but the sample code still generates errors everywhere in the code. For example.
ConverterProperties properties = new ConverterProperties(); Error on ConverterProperties
PdfReader pdfReader = new PdfReader(pdfStream); Error on PdfReader

Here is the code; copied form the link

     public System.Collections.ICollection GetFormFields(Stream pdfStream)
     {
         iTextSharp.text.pdf.PdfReader reader = null;
         try
         {
             PdfReader pdfReader = new PdfReader(pdfStream);
             AcroFields acroFields = pdfReader.AcroFields;
             return acroFields.Fields.Keys;
         }
         finally
         {
             reader?.Close();
         }
     }

     public void CreatePdf(String src, String dest)
     {
         ConverterProperties properties = new ConverterProperties();
         properties.SetCreateAcroForm(true);
         HtmlConverter.ConvertToPdf(new FileStream(src, FileMode.Open, FileAccess.Read),
             new FileStream(dest, FileMode.Create, FileAccess.Write), properties);
     }

I have no idea what link you are referring to and there is no indication how you are calling the two methods.

Below is an example that overrides the Web Form's Render() method.

 protected void Button1_Click(object sender, EventArgs e)
 {
     returnPdf = true;
 }
    
 protected override void Render(HtmlTextWriter Writer)
 {
     string Content = string.Empty;
     MemoryStream pdfStream = new MemoryStream();
     if (returnPdf)
     {
         using (StringWriter stringWriter = new StringWriter())
         {
             using (HtmlTextWriter HtmlTextWriter = new HtmlTextWriter(stringWriter))
             { 
                 base.Render(HtmlTextWriter); 
                 HtmlTextWriter.Close();
    
                 // get the page content  
                 Content = stringWriter.ToString();
    
                 //Get a PDF stream
                 MemoryStream htmlStream = new MemoryStream(Encoding.UTF8.GetBytes(Content));
                 HtmlConverter.ConvertToPdf(htmlStream, pdfStream);
             }
         }
    
         // render the PDF content
         Response.ContentType = "application/pdf";
         Response.BinaryWrite(pdfStream.ToArray());
         Response.End();
         Response.Flush();
         Response.Clear();
     }
     else
     {
         //Render HTML content
         using (StringWriter stringWriter = new StringWriter())
         {
             using (HtmlTextWriter HtmlTextWriter = new HtmlTextWriter(stringWriter))
             { 
                 base.Render(HtmlTextWriter); 
                 HtmlTextWriter.Close();
                 Content = stringWriter.ToString();
             }
         }
         Writer.Write(Content);
     }
 }

If the button is clicked a PDF is returned otherwise HTML is returned. I'm not sure if this is what you are trying to do exaclty.

Where is "returnPdf " defined?

Error: The name returnpdf does not exist in the current context.

I defined a public bool bool returnPdf to get rid of this error but still get the error on HTMLConverter and Encoding

MemoryStream htmlStream = new MemoryStream(Encoding.UTF8.GetBytes(Content));
HtmlConverter.ConvertToPdf(htmlStream, pdfStream);

Yes, I have both installed and added to the project but I get an error in the code:
using iText.Html2pdf

Error: The type or namespace 'iText' could not be found. I use the balloon and it give an option to change it to
using iTextSharp.Html2pdf but it gives a different error when selected.

Which .Net Framework do I need to have for iText7? 4.5 could be an issue.

Yes, understand iTextSharp is deprecated but VS 2017 shows that when I select "Show potential fixes".
I am just not been able to resolve these issues for some reasons. The code "using iText.Html2pdf;" gives error "using directive is not necessary.

Which .Net Framerwork is needed to use iText7? I googled but couldn't find the answer.