To complete the cluster creation, click Summary to see the configurations that you have provided, or download the Azure Resource Manager template that can be used to deploy your cluster. After you have provided the mandatory settings, the OK button becomes green and you can start the cluster creation process by clicking it:

You can see the creation progress in the notifications. (Click the bell icon near the status bar at the upper-right of your screen.) If you clicked Pin to Startboard while creating the cluster, you will see Deploying Service Fabric cluster pinned to the Start board.