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, 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 two-factor authentication.
Select Enforce on all users accounts.
Click Save. 2FA will occur on users' next sign-in.