https://authy.com/what-is-2fa/
two-step verification(2-Step Verification)
Two-factor authentication is a security best practice. It may be easy to steal usernames and passwords on a user's computer as they are typed, but it is extremely difficult to also target that same user's second factor device. This greatly enhances security because simple attacks to gather usernames and passwords are now almost worthless.
1.Microsoft Authenticator app
2.Google Authenticator
https://googleauthenticator.net/
3.zoho one
https://www.zoho.com.cn/accounts/oneauth.html
4.Tencent Authenticator
腾讯身份验证器(Tencent Authenticator)