I have followed all the instructions:
1. Uploaded the archive into the Moodle server
2. Extracted it into the 'mod' folder
3. Renamed the extracted folder into 'certificate'
4. Logged in with the administrative account.
5. Entered the 'Notifications' tab
6. ... and saw nothing there.
Then I checked the related documentation for plugin installations and changed the permission of the module to 'allow to run'.
Logged out and then logged in again.
Am I doing smth wrong?
Really looking forward to your reply.