Creating a variable involves defining a unique name, selecting the type, and setting the initial value (or initial content) for the variable:
In the Triggers panel, click on Manage project variables (X)
Click on the Create a new variable icon
Name your variable
Set the variable type
Set the initial value of the variable if it is a number or true/false variable
Click on OK
Tip
All variables must be uniquely named with no spaces or special characters, and the name of a variable is case sensitive. Once a variable is created its type cannot be changed.