OpenSSH server: how to configure keyboard-interactive authentication

You need to configure PAM for use with OPIE or OTPW, depending on your Ubuntu version. Once you have a one-time password system in place and properly configured via the /etc/pam.d/sshd module, then you can setup SSH to make use of it.

# /etc/ssh/sshd_config
PasswordAuthentication no
ChallengeResponseAuthentication yes

Don't forget to reload SSH after making changes to the configuration file; otherwise, your changes will not take effect.

Set

ChallengeResponseAuthentication=yes 

in your sshd.conf