To set or modify the value of any of the variables, click on that variable, as shown at the top of the screenshot on the right.
Different editors appear, depending of the selected variable type, such as in the example above, for Boolean variables.
Similarly, as dates are represented as integers, you can use the button with a small calendar to select a date as input value of an integer variable.
Whenever you change one of the input values, you must click on the green check button to confirm the change. Otherwise, the change will be assumed to have been canceled.