Can you set a notification/popup/modal to appear over the top of a PDF when a user opens it?

I would like to have a link on our website to open a using PDF Embed API. And when it opens on the screen I would like to tell them something in an alert/popup is that possible?

And if that is possible can you add links to do something like take them to a specific page in the pdf? Or can you set it to navigate to a specific page when they close the alert?