How to setup Yubikey login protection on Ubuntu

yubico_setup.sh

#!/bin/bash

# how to configure Ubuntu, see:
# https://support.yubico.com/support/solutions/articles/15000011355-ubuntu-linux-login-guide-challenge-response

# configure a yubikey
ykman otp chalresp -g 2

# associate a yubikey with your account
ykpamcfg -2

# ------------


# other way
sudo apt install libpam-u2f
mkdir ~/.config/Yubico
pamu2fcfg > ~/.config/Yubico/u2f_keys
# for additional keys run
pamu2fcfg -n >> ~/.config/Yubico/u2f_keys
# configure system to use U2F keys
sudo nano /etc/pam.d/sudo
# Add the line below after the “@include common-auth” line.
auth       required   pam_u2f.so
# configure system to use U2F keys for login
sudo nano /etc/pam.d/gdm-password
# Add the line below after the “@include common-auth” line.
auth       required   pam_u2f.so