How to Enable Two-factor Authentication for SSH in Fedora Linux

Install Google-Authenticator on Fedora 30 server using the command:

1. $ sudo dnf install -y google-authenticator.
2. $ google-authenticator.
3. Do you want authentication tokens to be time-based (y/n) y [Enter' Y' here]
4. Do you want me to update your "/home/linuxhint/.google_authenticator" file? ( ...
5. $ sudo vi /etc/ssh/sshd_config.