We have put together a REST API so customers can dynamically update their DNS.
The API, documentation and usage examples are available here: https://public-api.sonic.net/dyndns
Note this is only available via https not http.
Since this is a labs project please direct any questions to the forum as Support will not be able to assist you.
We do have some example code hosted at GitHub here: https://github.com/augieschwer/SonicDynDNS