1. Reserve the FMC sandbox from : https://devnetsandbox.cisco.com/RM/Topology (search for FMC)
2. Download python 3.x.x if you dont have in your local system : https://www.python.org/downloads/
3. Do a "pip3 install json ; pip3 install requests ; pip3 install sys" , to complete the library pre-requisite installs.
4. Download the .py file from : https://github.com/Devanamapriyan/CS-security-demo/blob/master/security-API-demo.py and save it locally.
5. From the reserved FMC sandbox in Step1, navigate to toolbar option "window > output" to get username and password for the current session.
6. Edit the username and password values mentioned in the downloaded github python file with the one from step4 and save it and run from cli : python3 <path of .py file> eg. python3 security-API-demo.py