Fro example, I use these commands. Is it right?
sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/nginx/nginx.key -out /etc/nginx/nginx.crt (generating a self-signed certificate)
sudo openssl dhparam -out /etc/nginx/dhparam.pem 2048
sudo nano /etc/nginx/sites-enabled/default //(uncomment listen 443 ssl default_server; and change server_name _; ssl_dhparam /etc/nginx/dhparam.pem;)\
//(add ssl_certificate /etc/nginx/nginx.crt; ssl_certificate_key /etc/nginx/nginx.key; )\
sudo nginx -t
sudo service nginx reload
sudo apt-get update
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:certbot/certbot
sudo apt-get update
sudo apt-get install python-certbot-nginxsudo certbot --nginx