Failed to search registration and hosting information

Hi, how are you? Could someone help me with this error? I’m trying to add a domain, but this message appears : "Failed to search (domain) registration and hosting information at this time. Please contact Cloudflare support or try again later. I’m new to these subjects and I don’t understand the reason for the mistake. Thank you very much in advance.

If it’s a Freenom domain, there’s already plenty of information on that issue. Freenom needs to fix their broken WHOIS server.