Lets Encrypt

sudo apt update

sudo apt install python3-certbot-nginx

sudo nano /etc/nginx/sites-available/your_wildcard_name.example.com

sudo apt-get install ufw

sudo ufw enable

sudo ufw allow 'Nginx Full'

sudo ufw allow http

sudo ufw allow https

sudo ufw status

Your status should now look like this:

Output

Status: active

To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Nginx Full ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Nginx Full (v6) ALLOW Anywhere (v6)

sudo certbot certonly --agree-tos --nginx -d *.example.com -w /home/pi/domoticz/www/ -w /var/lib/letsencrypt/

sudo cat /etc/letsencrypt/live/example.com/privkey.pem >> /home/pi/domoticz/server_cert.pem

sudo cat /etc/letsencrypt/live/example.com/fullchain.pem >> /home/pi/domoticz/server_cert.pem

sudo cp /home/pi/domoticz/server_cert.pem /home/pi/domoticz/letsencrypt_server_cert.pem

sudo /etc/init.d/domoticz.sh restart

sudo cat /etc/ssl/certs/dhparam.pem >> /home/pi/domoticz/server_cert.pem

cd /etc/ssl/certs

sudo openssl dhparam -out dhparam.pem 2048 #bit long safe prime, generator 2

sudo cat /etc/ssl/certs/dhparam.pem >> /home/pi/domoticz/server_cert.pem

sudo /etc/init.d/domoticz.sh restart

crontab -e

0 23 * * 5 sudo certbot-auto renew --webroot -w /home/pi/domoticz/www/ --deploy-hook /home/pi/domoticz/scripts/deploy-cert.sh >/dev/null

#Check Status of certificates
sudo certbot certificates

#This one is working for my system

sudo certbot --nginx

sudo certbot --authenticator standalone --installer nginx -d example.com -d *.example.com

# To obtain and see SSL Certificate expire date
sudo certbot renew --dry-run

or

#To renew SSL Certificate manual
sudo certbot certonly --manual

or

#To renew SSL Certificate manual
sudo certbot renew --cert-name example.com -d example.com -d *.example.com
or
sudo certbot certonly --cert-name example.com --nginx -d *.example.com-d example.com

or

sudo certbot --authenticator --installer nginx -d example.com -d *.example.com --pre-hook "systemctl stop nginx" --post-hook "systemctl start nginx"