-it is simple if you have python installed on your machine

-you need to run Calculator.py in terminal

-by typing 'python' for windows and 'python3' for Linux

-it will go like this 'python Calculator.py' or 'python3 Calculator.py'

-this will give you GUI and fill in the required information

-like age, gender, height, and weight

-Popup will show your BMI

-if you didn't install python on your machine.

-here is the installation guide https://realpython.com/installing-python/ please refer to it.