How to add an item to a bracket that already exists?

[aspauldingcode]

I know I can run:

sketchybar --add bracket lbracket apple space '/space\..*/' separator_left front_app left \
  --set lbracket "${brackets[@]}"

But since I've already run that, when I add a new item, space.2 for example, I'm trying to get it to add into the bracket.

But, it is not adding to the lbracket.