2-factor authentication (2FA) adds an extra layer of authentication for users signing in with email and password. 2FA is not required for those signing in using Single Sign-on (SSO).
At the moment, 2FA is optional for your users, however, you can enforce 2FA for your Method account. To do that, follow the below steps.
Click your Profile icon in the upper-right and then click Account Settings.
Click User Settings.
Below the user grid, click the button Enable 2FA.
Select Enforce on all users accounts.
Click Save. 2FA will occur on users' next sign-in.