Extension relies on obsolete hook - will not continue working
I'm not sure how this extension differs from the NotePermissions extension, but it will need the same sort of update as the other one to continue working.
The big problem is that the main hook this extension uses is obsolete and doesn't really work (never worked well to begin with as it only affected the contact summary screen and not searches, reports, the api, or anything else). Here is the docs to update code to use the new hook instead: https://docs.civicrm.org/dev/en/latest/hooks/hook_civicrm_notePrivacy/#before