looks like you have created only one TXT entry - https://check-your-website.server-daten.de/?q=orbit8.com#txt
Your command has two domain names.
So two different entries with the same domain name _acme-challenge.orbit8.com
and two different TXT entries are required.
If you overwrite the first entry with the second, the validation fails.
Wait one hour, start again, add both entries,recheck your domain to see, if you have now two rows with
looks good, correct length, correct characters
If yes, next step.