2FA, two factor authentication. On HashNest they are google authenticator verification and SMS verification. HashNest strongly suggests users to apply for both to ensure the accounts safety and avoid hacking.
Steps as follow:
First of all you need to download Google authenicator from google play or app store on your phone.
Google authenication verfication setting
SMS verficaiton （More: If you have applied google authentication verification, it will request you to input google code too.)