wget https://dl.eff.org/certbot-auto
chmod a+x certbot-auto # executable authority
./certbot-auto certonly -d "*.xxx.com" -d "xxx.com" --manual --preferred-challenges dns-01 --server https://acme-v02.api.letsencrypt.org/directory
dig -t txt _acme-challenge.xxx.com @8.8.8.8
openssl x509 -in /etc/letsencrypt/live/xxx.com/cert.pem -noout -text
certbot-auto renew #Valid for 90 days