Hi,
I want to add my domain name to my hosting account, and I point it to the InfinityFree nameservers. But I get an error which says that the name server is not responsible for this domain. I have checked with my domain provider and they said that maybe the name servers are not correct.
If your domain does not have any of the extensions that force this system, try finding a “DNSSEC” setting in your registrar and disabling it. I see you’re using STRATO, which offers a “Domain Guard” service; disabling it should help: