I have created a catalog page with all the 3D Flipbooks, it seems to work on the backoffice but not on the front end.
Our visitors, when clicking on the page do not have the pdf flipbook. It's only a ur ending with "#"
Here is the page : https://www.dynseo.com/tous-les-catalogues-et-fiches-techniques-pdf/
we cannot find any 3d flipbook instances on your page.