Here is what my hoster wants from me:
"There is a problem with the nameservers that have been provided in regards to the Cloudflare service. They do not have any records for your domain name at the moment, which means that they cannot be set for your domain name.
You need to check with Cloudflare directly and ask them to make sure that the Nameservers they have provided you are correct and that there is a DNS zone for the domain name vital-generation.de on their server.
Once they do, please update this ticket with the desired nameservers so that we can check and add them on your behalf. Due to the regulations and requirements set from the DE registry, nameservers changes can only be done from our end which is why you are unable to process a change from your user area. Instead, when you try to do so, a request to us is submitted."