Hi Al,
This forum is specifically for questions about Corvid by Wix,
Are you using code on your site? If so please send us a snippet of the code that you are having issues with, and we will be happy to take a look.
As I said in my other post, you can use the PDF Viewer app in a lightbox, link the button to that lightbox. You can update the PDF file that is displayed in that app and keep the same link.
If you are not adding code to your site and need more assistance please contact Wix Support .
Thank you!
Dara | Corvid Team