Certbot custom validation
certbot certonly
--manual
--preferred-challenges=dns
--manual-auth-hook /path/to/dns/authenticator.sh
--manual-cleanup-hook /path/to/dns/cleanup.sh
-d secure.example.com
--manual-public-ip-logging-ok
-n
certbot certonly --manual --preferred-challenges=http --manual-auth-hook /home/tunnel/scripts/certbot/auth.sh -d webing.webit.lv -n --manual-public-ip-logging-ok