Hi @VickyC112 ,
hm. When thinking about PDF and PDF reader software, this software is able to detect mail addresses and URLs from analyzing the readable contents of a PDF where you, on the InDesign side, have to do nothing. Well, nothing but to make sure that text is still text after the PDF is written.
Let's switch to Publish Online. Here we have a different thing. All editable text on a page is exported as outline paths in SVG format. It's not text anymore when presented with Publish Online, it's just graphical content you can read.
So the reader software cannot see text as text and cannot check for possible hyperlinks.
That means, you have to do the hyperlinks on the text and on graphic frames with InDesign's hyperlink features. Select some text, the text of an URL in your story and use the Hyperlinks panel to create a hyperlink. This kind of hyperlink should also work with Publish Online.
Regards,
Uwe Laubender
( Adobe Community Professional )