sudo apt update
sudo apt install libpam-google-authenticator

google-authenticator

sudo nano /etc/pam.d/sshd

auth required pam_google_authenticator.so nullok

vim /etc/ssh/sshd_config

KbdInteractiveAuthentication yes
PasswordAuthentication yes

sudo systemctl restart sshd

登录时如有验证失败的问题，检查有无输入验证码的交互，检验sshd_config配置