Generate SSL cert Let's Encrypt - certbot

[aizu]

# apt install certbot python3-certbot-nginx
# certbot --nginx -d example.com -d www.example.com

Certbot will modify nginx /site-available/default file, and append the 443 entry.

It also will install certbot's service for auto renew.

# systemctl status certbot.timer

To test the auto-renew.

certbot renew --dry-run

Ref: https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-20-04