Use curl, maybe put it on interface up, if changes.
https://dynamicdns.park-your-domain.com/update?host=radio&domain=securityrabbit.com&password=<passowrd>&ip=<current-ip>
Example:
https://dynamicdns.park-your-domain.com/update?host=radio&domain=securityrabbit.com&password=c899a100d51340dc80b58d60beba82a8&ip=66.58.208.101