Along with a visible alert to new events in the notifications menu, users can configure how they are notified of new events from their notification preferences page accessed from the user menu or from the profile icon in the notifications menu.
Click the drop down menu v of your Profile and select Preferences
In the User account section select Notification preferences
Notifications may be sent via the web (when logged in to Moodle), email and mobile.
Some notification settings are locked and cannot be switched off. Notifications that can be turned on and off have a button.