Calibrating Charuco Board size not possible?

[weltraumimport]

Hi! I'm trying to follow this Calibrate Camera documentation here: https://normanderwan.github.io/ArucoUnity/manual/calibrate-a-camera.html
and underneath fig.2 it says "Configure the calibration board object by measuring the one you just printed : units are in meters this time. The ArucoObjectDisplayer helps you visualize the configured board to see if it's match with the printed one. Don't switch x and y values." but i can't change any of the values on the ArucoObjectDisplayerImagePlane object at all. I tried changing the ArucoCharucoBoard object as well but it doesn't change as well. I might be completely misunderstanding so if someone could clear it up for me it'd be really appreciated!