> For the complete documentation index, see [llms.txt](https://oten.gitbook.io/identity-support/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://oten.gitbook.io/identity-support/user-guide/account-management/account-security/multi-factor-authentication-optional.md).

# Multi-Factor Authentication (optional)

- [2FA-Email verification codes](https://oten.gitbook.io/identity-support/user-guide/account-management/account-security/multi-factor-authentication-optional/2fa-email-verification-codes.md)
- [MFA-Authenticator apps (TOTP)](https://oten.gitbook.io/identity-support/user-guide/account-management/account-security/multi-factor-authentication-optional/mfa-authenticator-apps-totp.md)
- [MFA-Passkeys (FIDO2 / WebAuthn)](https://oten.gitbook.io/identity-support/user-guide/account-management/account-security/multi-factor-authentication-optional/mfa-passkeys-fido2-webauthn.md)