A Microsoft file hosting and synchronization service.
So I finally managed to get OneDrive working on Catalina 10.15.7. I Uninstalled the current version of OneDrive. Opened OneNote then selects "Help > check for updates" and turned off the Automatic Update in preferences. I then installed version 23.002.0102.0004 of OneDrive and bingo... it started and is now happily updating.... Hope this works for you too.
This seems to work for me (OneDrive is now syncing). Important is that the automatic updates must be set to OFF in OneNote. Restart required after changing this setting, otherwise OneDrive updates itself before you know.
I hope this will last till a correct update is coming.
Thank for the tip (I had nightmares before).