It must be a small typo if not resolved yet. The height of the SizedBox should be 12.0 not 120.0 according to the description. The gap between the two TextFields should be smaller.
I've just recognized that the case might be that we have to create the second SizedBox with height 12.0, although the text only says to create the two TextFields.
It must be a small typo if not resolved yet. The height of the SizedBox should be 12.0 not 120.0 according to the description. The gap between the two TextFields should be smaller.