I just needed to scroll down all my notification history on Facebook which was a PITA to do manually so I am looking for a way to automate this. Basically I want to send End 100 times in a row with 1 seconds pause inbetween (or some other solution with the same effect).

I have found several lists of extensions and bookmarklets that almost offer what I am looking for, e.g.,

https://www.thewindowsclub.com/auto-scroll-a-web-page-down-or-up

https://addons.mozilla.org/sv-SE/firefox/addon/auto-scroll/

https://helpdeskgeek.com/how-to/automatically-scroll-down-pages-in-your-web-browser/

but they all fail on one importan requirement: they don't work in the background. I want to set the tab to start scrolling and then switch to another tab.

Can this be done in Javascript as a bookmarklet? (Bookmarklet isn't necessary, I just assume that is the most likely solution)