Freenom stopped domain registrations several months ago. Netcraft has reported a drop in phishing emails blocked with Freenom domains
www.netcraft.com/blog/impact-of-freenom-halting-registrations-on-cybercrime/#:~:text=Freenom%2C%20which%20offers%20free%20domain,domain%20registrations%20in%20March%202023 .
Some are looking to other free domain providers such as pp.ua or eu.org
nic.eu.org/
dyn.addr.tools has a simple DDNS method
There are other related tools challenges.addr.tools dns-01 ACME challenge helper zone dyn.addr.tools simple dynamic DNS for your own domains, no account required header-echo.addr.tools view HTTP request headers, modify HTTP response headers info.addr.tools explore identifying information for domain names and IP addresses ip.addr.tools construct domain names that resolve to any given IP address myip.addr.tools get your external IP address dnscheck.tools identifies your DNS resolvers, checks DNSSEC validation, and more
dyn.addr.tools/
dnscheck.tools/#more