There are three domains available. Each one of them works under a certain scope.
Malware blocking
security.cloudflare-dns.com
Malware and adult content blocking (including search results)
family.cloudflare-dns.com
Internet privacy (adult content is accessible)
one.one.one.one
When neither DoT nor DoH are available
If your home wi-fi router/modem does not support DoT nor DoH, you can still change the default DNS settings by pointing to the IP addresses below. With that done, your family will be secure against malware and adult content. Privacy will be limited though as your ISP (mainly) and other computers from the Internet will know the websites you have visited.
Primary DNS 1.1.1.3
Secondary DNS 1.0.0.3