I recently picked up a new domain strictly for my home network and experimentation. I bought it from Google Domains again. One option they have is dynamic DNS for no additional fee. I thought I'd give it a try, but their documentation leaves a bit to be desired. I was setting it up in pfSense which does not have a specific setting for Google or for the dyndns2 protocol that they use. Fortunately user switchman over at the pfSense forum was able to provide a straight forward answer:
Here is a link to the entire thread: Topic: pfSense Dynamic DNS and Google Domains Dynamic DNS service
I hope you find this little tidbit helpful!