Hi there,
I'm trying to achieve the same on PrestaShop 1.7
The first solution Catalog > Attachments > Add new, seems to only allow file to be attached to a product.
The second solution doesn't seem to work. The PDF file is there in cms/img but I can't see it when I try to add a media (I reckon it allows only images).
Anyone with another solution?
Thanks!
EDIT: I reckon I found a solution, use Add a link instead of Add a media, next to the URL field there is button to add file!