How to load a PDF file from an URL via TWebBrowser

Question

I have a extracted an URL from an iframe in an HTML page online with TWebBrowser and this URL retrieves a PDF file. How can I save this reply in a File locally by using TWebBrowser?

The line in the String content4 := WebBrowser4.OleObject.Document.documentElement.innerHTML; looks like this:

                <iframe name="msdsPageFrame" width="1000" height="1200" id="msdsPageFrame" src="/MSDS/MSDS/PrintMSDSAction.do?name=msdspdf_210370071046219" style="z-index: 1;"></iframe>   

Here is a demo source in Delphi 10.1 with TWebBrowser ZIP-Standard_Delphi_10.1