The default configuration /etc/ssh/sshd_config
must contain Include /etc/ssh/sshd_config.d/*.conf
curl -fsSL https://raw.githubusercontent.com/ioqy/ssh-server-hardening/master/install.sh | sudo bash
or
wget -q -O- https://raw.githubusercontent.com/ioqy/ssh-server-hardening/master/install.sh | sudo bash
sudo "/usr/local/bin/uninstall-ssh-server-hardening.sh"