In Smart Cloud, you can use Extensibility when SDx is implemented on-premise as it works in exactly the same way as in the standard SDx Web Client implementation. However, some infrastructure work is required to be done by the Smart Cloud Support Team to fully configure your implementation.
The Smart Cloud Support Team must set up an existing estate to get the Cloud server talking to your company's infrastructure on-premises system. Once the configuration is done, Extensibility for both the server side and the client side is the same as a standard SDx Web Client implementation.
For information on extensibility configuration, please contact the Smart Cloud Support Team, see Contact the Smart Cloud Support Team.