Fill in the fields in the modal as follows:
- Key The key name that allows the variable to be defined (Example: user_id, language)
- Value: The data that the variable will hold. (Example: 12345, English)
- Read Only: Determines whether the variable is read only (if checked, the value of the variable cannot be changed during the session).
Add a new variable by clicking the ADD button and save it with the SAVE button.
