Secure server settup (optional)

this method can skip...!!

sudo adduser <admin> --disabled-password -q
sudo usermod -aG sudo <admin>
sudo -u <admin> bash -c 'mkdir -p ~/.ssh && echo "YOUR_PUBLIC_SSH_KEY" >> ~/.ssh/authorized_keys && chmod 700 ~/.ssh && chmod 600 ~/.ssh/authorized_keys'

echo "<admin> ALL=(ALL) NOPASSWD:ALL" | sudo tee -a /etc/sudoers

su - <admin> -c 'sudo sed -i "s|^PermitRootLogin .*|PermitRootLogin no|" /etc/ssh/sshd_config'
su - <admin> -c 'sudo sed -i "s|^ChallengeResponseAuthentication .*|ChallengeResponseAuthentication no|" /etc/ssh/sshd_config'
su - <admin> -c 'sudo sed -i "s|^#PasswordAuthentication .*|PasswordAuthentication no|" /etc/ssh/sshd_config'
su - <admin> -c 'sudo sed -i "s|^#PermitEmptyPasswords .*|PermitEmptyPasswords no|" /etc/ssh/sshd_config'
su - <admin> -c 'sudo sed -i "s|^#PubkeyAuthentication .*|PubkeyAuthentication yes|" /etc/ssh/sshd_config'
sudo systemctl restart sshd

sudo apt install -y ufw
sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow ssh
sudo ufw enable

change <admin> to your own user name