ruleX in between 2 bar chart categorical points

[rht]

In the bar chart of https://greatcarbonarbitrage.com/climate_financing.html, I want to add a dashed vertical line between the "Emerging Market Countries" and "Asia" bar, dividing the bar chart into 2 areas. I am not able to do this, because I can't use any number to signify the location of this vertical line, unlike a simple horizontal line via Plot.ruleY([0]).

(note that since the x points are not floating numbers, I can't seem to place a random text via Plot.Text either)

Plotting code of the bar chart: https://github.com/ox-inet-resilience/carbon_arbitrage/blob/a851e399618c63eda29fe6e488b0de5c620c12eb/js/climate_financing.js#L83-L111

Appreciate the help!