Split violin plot with single x value

Im trying to merge 2 different violin plots into one split violin plot. But it doesn’t look like the ones in the documentation of split violin plot(https://plotly.com/javascript/violin/#split-violin-plot). It is separated to two sides. But i want them to have no space in between two sides. Here is a simple example of how it looks like.

How can i merge them so that there is no space in between 2 sides?