Under the Options column > Text Options, the base (XS) alignment allows you to choose left justified, center justified, right justified, and justified. But when expanded to show SM, MD, LG and XL options, only left, center and right are available. There should also be a justified button option for each of these sizes.
Generally, you don't use justified at (XS) mobile size anyway, because it leaves lots of large white gaps between words. Justified is more appropriate for MD screens and up.
I realize you can do this with CSS and media queries, but it would be a whole lot easier to just have the fourth button added to all the screen sizes.