Setting up your sandbox is a piece of cake with the DevNet Sandboxes. Check out this link here to set up a Identity Services Engine Sandbox and try out your API calls there.
There will be API Documentation for ISE at developer.cisco.com you can reference as you go along.
Happy Labbing!
Getting Started
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: