The base addons folder is your windows user's documents folder located at the c:\users\your windows username\documents directory.
If you want to move the addons fodler you need to move the windows documents folder, but there are several other programs using this so only move it if really necessary (the internet explains how to do this, e.g.:
https://www.windowscentral.com/how-m...ive-windows-10 )
It also explains what Sharlikran wrote above: Disable OneDrive protection and sync with your users documents folder! ESO does not like that so better deactivate that.
The links I posted above describe how to find that folder.
The game will create the live/AddOns folder the time you start the game and login to the overland the first time!
You can also manually create the AddOns folder (case sensitive!) before that if you like to.