To add 2FA to your own account, go to Settings → Security → Two-factor authentication and choose an authenticator app or SMS. Scan the QR code with an app like Authy or Google Authenticator, enter the six-digit code to confirm, and save your backup codes somewhere safe.
Admins can require 2FA for an entire organization under Admin → Security. If you lose your device, use a backup code to sign in, or ask an admin to reset 2FA on your account.