Google Domains. Login to your Google account and visit the domains portal at https://domains.google.com. Find the domain you wish to use and click on the DNS button. Under the Synthetic records section, click the dropdown and select Dynamic DNS. In the Subdomain field, enter what you wish this FQDN to be (ex. home.example.com or camp.example.com).
Why are photosynthesis and cellular respiration considered opposite reactions