Separator in X-axis and 2 Box plots per range

Hello everyone,

Currently I have 2 sets of data: Type A with 3 sizes(1 kg, 2 kg, and 3 kg), and Type B with similar sizes(1, 2, 3 Kg). Each weight has multiple value to draw a box plot. I want my box plot to be similar as shown below but have no idea how to, first, separate x-axis with vertical lines and, second, put 2 box plots of the same weight in a range. Below is a similar figure I want my figure to be.

How can I do this one?

Thank you, Huy Nguyen.