I hurriedly bought a pump some years back and have never been able to
use it.

https://www.flickr.com/photos/79018230@N05/49860238831

It has an external thread so I guess something is supposed to fasten
on to it.

I've put a standard Schrader/Presta adapter alongside for scale
purposes only. The pump has no internal thread(s).

--
AnthonyL

Why do scientists need to BELIEVE in anything?