Usually, you should change the Organization Notifications Settings instead of the User Global Notification Settings. Learn more about Organization Notifications Settings.
However, if you want, each user can change the user global minimum severity level. This can be changed in the App:
- Click on Menu in the tab bar
- Click on your name in the top
- Click on Notifications on the right
- Now you can select the alert severity required to receive a notification.
Note that the user setting is taken into consideration after the organization setting. So if the organization minimum severity setting is Error and a Warning is issued, the user will never receive the notification no matter what is the user setting.