The domain is using the CloudFlare nameservers.
ON Cloudflare I have added the A-record for @ to 75.2.60.5 and CNAME for www to to point to derbauernhofkindergarten.netlify.app
Netlify has verified and seems happy with the external DNS settings.
Yes, I was aware of propagation, so I used https://dnschecker.org to check whether the changes have been propagated. It seems that even when https://dnschecker.org is fine, it still needs more time to make sure it is reflected everywhere.