Two-factor authentication lives on the Security page in your practice settings, and it is one switch: Enforce two-factor authentication. Turn it on and it applies at once. Every member of the practice confirms their sign-in with a six-digit code from an authenticator app, and anyone signed in without one is asked to sign in again. There is no per-user setting to forget, and nobody can opt out.
If you already use two-factor authentication yourself, you stay signed in after saving. If you don't, Sodium signs you out so you can set yours up first — the same way everyone else will.

