Thanks a lot..
Installed as you suggested on a dummy site.. it's working fine..
2)
On dummy site , there is no NOTIFY plugin, I added an email address in setting of your plugin, but still it's not sending email.
3)
Noted about signup plugin... Tried it, but uninstalled it..
Thanks a lot for awesome plugin.. I am sure you will update it for Moodle 4 too..
Thanks again..