Is the author of pdf-lib okay? (github.com)

If one needs to work with pdf in a JS environment one will sooner or later cross paths with pdf-lib. I noticed the last release was almost 5 years ago and the maintainers git contributions stopped at the same time. There is a second github account under the same name but the last contribution was in 2024.

Also his personal homepage (https://andrewjdillon.com/) seems to be no longer under his control, the certificate has a different CN and the websites domain is listed under the SAN (with a multitude of other domains).

Why would you think he is not ok? Just linking to a GitHub repo he maintains doesn't really tell the story.

What if he/she doesn't want to be bothered any more or is not interested in it? Or whatever else?

Go clone the repo and work on it.

Sounds like there's a fork where some maintenance is still going on:

https://github.com/Hopding/pdf-lib/issues/1720