In case you have to:
- add a user: sudo prosodyctl register <username> <server-url> <password>
- delete a user: sudo prosodyctl unregister <username> <server-url>
to list users: prosodyctl mod_listusers
- Maybe you need to install an add-on module http://prosody.im/files/mod_listusers.lua
- (Just copy the lua code to /usr/lib/prosody/modules)