Arrow 1 = Enter the number of steps. The width of the tread. As well as the height of the step, that is, from the top of one step to the top of the next step.
Arrow 2 = If you use method # 1, then the boxes (x, y, z) of method # 2 are disabled. You must use a single method at a time. To change the method, delete your data from Method # 1 and go to Method # 2 or No. 3.
Arrow 3 = Once the existing measurements are registered, click the "Make stairs" button.