The add-on does not collect any data on the user and does not share anything to anyone. It has no home server and does not embed any analytics in its code.
All remote server calls are done towards novelupdates.com in order to get the user's reading lists and chapter update status, information which is then stored locally in the user's browser. Cookies or login information are not stored in any way by the extension.
The extension uses but is not related in any way to novelupdates.com, which has its own privacy policy.