I’ve helped a few people in the past. One of the topics used import processing.video.*;. I can not remember that I had to install that library specifically (possibly I did use of version of Processing IDE 3.x) but I might be mistaken. However today I had to manually install the library.
I do not know if this is due to an oversight when the Processing IDE is build or if the approach by the developers has changed. I found a topic going back to May 2022 (Video library simply missing?) so it seems to be an old issue.
If this was not due to an oversight I would like to suggest that a note is made in the library reference (Video / Libraries / Processing.org) that this library has to be installed manually.
If it was due to an oversight I did expect it to be fixed by now
But if nobody tells the developers … Where can I report this? https://github.com/processing/processing4/issues?
The same applies to the sound library (and there might be more).
Remark:
What is strange (to me) is that some libraries (e.g. Serial or PDF Export) do not require manual installation.