// Ubuntu 20.04
sudo apt install certbot python3-certbot-nginx
// Ubuntu 18.04
sudo add-apt-repository ppa:certbot/certbot
sudo apt install python-certbot-nginx
// Configure ufw
sudo ufw allow 'Nginx Full'
sudo ufw delete allow 'Nginx HTTP'
sudo ufw delete allow 'Nginx HTTPS'
sudo certbot --nginx -d example.com
sudo add-apt-repository ppa:certbot/certbot
sudo apt install python-certbot-nginx
sudo certbot --nginx -d example.com -d www.example.com