ASP.Net: Add digital signature in PDF

I have a pdf document embedded on my razor page. I want the users to sign the document digitally. Normally, when I open the pdf document using adobe, I can see a menu bar saying "sign document by typing or drawing signature", something like this:

I am not seeing anything like this when I embedded the pdf document on my razor web page.

Below is my code, I used to embed the pdf document:

public IActionResult Index()
{
    using (MemoryStream stream = new MemoryStream())
    {
        string embed = "<object data=\"{0}\" type=\"application/pdf\" width=\"1000px\" height=\"1000px\">";
        embed += "If you are unable to view file, you can download from <a href = \"{0}\">here</a>";
        embed += " or download <a target = \"_blank\" href = \"http://get.adobe.com/reader/\">Adobe PDF Reader</a> to view the file.";
        embed += "</object>";
 
        TempData["Embed"] = string.Format(embed, "/BlankPDFFiles/Test.pdf");
        return View();
    }    
}

This is an intranet application, Is there any way, I can have the employees sign the pdf document that is embedded on the web page.

Any help will be greatly appreciated.