Letsencrypt : Secure Apache on Ubuntu 20.04

Let’s Encrypt is a Certificate Authority (CA) that facilitates obtaining and installing free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers.

1. Installing Certbot

#sudo apt install certbot python3-certbot-apache 

2.Checking your Apache Virtual Host Configuration

#sudo vi /etc/apache2/sites-available/your_domain.conf
#sudo apache2ctl configtest
#sudo systemctl reload apache2

3.Allowing HTTPS Through the Firewall

#sudo ufw status
#sudo ufw allow 'Apache Full'
#sudo ufw delete allow 'Apache'

4.Obtaining an SSL Certificate

#sudo certbot --apache 

5.Verifying Certbot Auto-Renewal

#sudo systemctl status certbot.timer 

- To test the renewal process
#sudo certbot renew --dry-run

source: 

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