Read the uper part how to find your addon folder please:
https://www.esoui.com/forums/showthread.php?t=8858
The sreenshot idea is basically showing you where your addons need to be!
And search for eso + OneDrive and check if a windows update has enabled OneDrive for you, moving your users folder there as well.
You can disable moving the users folder to onedrive in the OneDrive settings but there are plenty of online discussions about it as well.