For the ones finding this post via searched:
There exist sticky forum threads here in the ESOUI "addon help" forums (
https://www.esoui.com/forums/forumdisplay.php?f=164) about e.g. "how to find the addons folder", including the screenshot advice that ExoY provided you, as well as info about OneDrive (as the link above includes Microsoft OneDrive):
https://www.esoui.com/forums/showthread.php?t=8858
-> Where do I need to install/extract the addon zip files to? Or what is the "/live" folder?
-> Why can't I see any addons inside the game's AddOn manager?