How do I have gallery-dl look for a specific extension?

[plshelpidkwhatimdoing]

I'm trying to download the recently released jfk files (2.3k pdfs) and gallery-dl doesn't show the pdf urls when I use the generic extractor. I also tried the ao3 extractor just on the off chance it would work, and it didn't (unless I used it wrong, I put ao3:https://www.archives.gov...). Is there a way to tell the extractor to look for a specific extension (in this case pdfs), or is there something else (like a pdf extractor)?

[mikf]

There is currently no option to scan a webpage for files with a specific filename extension.
You could try wget with -A.pdf instead: wget -r -l1 -nd -A.pdf <URL>

[plshelpidkwhatimdoing]

That will work. Thanks.