Add Site failed

Hi!
I want to use Cloudflare for free domain hosting, but I get this error when I want to add the domain, “Failed to lookup register and hosting information of king-arthur-stone.ro at this time. Please contact Cloudflare Support or try again later”.
And in the topics on the platform I read that there is a problem related to the configuration of the Nameservers, only that I cannot configure them until I add the domain and receive the nameservers from Cloudflare… I also found out that before a domain can be added to Cloudflare, it must return a valid SOA record and NS records for valid, working nameservers…
Please, does anyone know what I can do to solve this problem?
I mention that my domain is .ro

What did you do?