SSL Wildcard CERT:
sudo apt install certbot
certbot certonly --manual --preferred-challenges dns --server https://acme-v02.api.letsencrypt.org/directory --manual-public-ip-logging-ok -d '*.hg-system.com'
Go to your DNS Provider for e.g. Cloudflare insert the txt record „_acme-challenge“ insert the code from the command ahead,
wait for at least 2 min or till the DNS-Record is available and press enter (in some cases you need to wait longer)