An extra layer of security can be added to your school by turning on two-factor authentication (2FA). This can only be required for school employees, so not for students. It requires every employee to have access to his/her phone when logging in. This means even if someone's password is compromised or stolen, only that person can log in to his/her account.
2FA can be turned on in the settings menu of your school. Be sure to be in the menu of your school before going to the menu, otherwise the option Settings is not available. After clicking Settings in the menu, go to the bar 'Security'. Here you will find the option Two-factor authentication which can be turned on by the switch on the right. The page will automatically save and refresh after clicking the switch.
2FA can also be turned on by a user individually for himself, read this article to find out how.