Can Kopernio export PDF to Zotero?

Hello! When I attempt to export to Zotero from Kopernio, the PDF is not being saved in the reference that is created in Zotero. Instead, I get a reference that contains a snapshot, which navigates to an online link that contains the PDF. Perhaps worth noting that when I export, a new tab is opened that seems like it might be a PDF download but only contains about:blank.

Since I use Preview for note-taking, it would be great to have the PDF actually downloaded when exporting to Zotero, and I get the impression that this is supposed to occur (usually Zotero will download PDF when not using Kopernio). Is there a way to fix this? I'm using Firefox on a Mac.