The domain does not return valid name servers. In order to add a domain to Cloudflare, the domain must first be delegated to valid nameservers. Either park the domain using the registrars default nameservers or delegate to a third party DNS provider temporarily. Either action will allow you to add the domain.
Use the following website to test if there are any nameservers resolving for your zone. If you enter your domain name and click on the button, this should show you the nameservers for your domain: Dig web interface .
The domain is not registered. Run a whois command to verify if the domain is valid, $ whois example.com .
Thank you so much. I already contact GoDaddy regarding on this. And ask them the status of my domain especially [https://icann.org/epp#clientHold ]. I will wait another 24hrs so that the domain will be propagate.