Webcam not visiable in lightburn

i went into tools - calibrate camera lens but i dont see a capture button.i see the list with my camera in it and if i select it i can choose standard and then the dropdown box does now show a list of different settings.
am i guessing that i will need to do (none- do full calbration) and use the black dots on the machine?just that im not with my machine so if thats it then ill have to do that in the morning.thanks