Sure but if you have a static IP, you don't need such plugin... DynDNS is only need for home servers with a dynamic IP.
Mh, I think you might watch from a different angle.
As far as I remember, this plugin acts as de facto DynDNS-Service - not to use i-MSCP behind dynamic IPs but to assign dynamic hosts to clients via i-MSCP.
Your services with dynamic IPs connect via an API key to the i-MSCP-Plugin (which of course should have a static IP) which then updates its DNS entries for the clients with any new assigned IP.
TL;DR:
Afaik, OwnDDNS acts as privately hosted dynamic DNS service inside your i-MSCP instance for third party clients with dynamic IPs.