@DanH found it in the LAF Docs: https://docs.hise.audio/glossary/custom_lookandfeel.html#getting-started
laf.registerFunction("drawNumberTag", function(g, obj) { obj.area[0] += obj.area[2] - 16; obj.area[1] += 2; obj.area[2] = 14; obj.area[3] = 14; g.setColour(0x88000000); g.fillRoundedRectangle(obj.area, 4); g.setColour(Colours.white); g.drawRoundedRectangle(obj.area, 4, 2); var letters = ["A", "B", "C"]; g.drawAlignedText(letters[obj.macroIndex], obj.area, "centred"); });And make sure to put in the below as well
const var laf = Engine.createGlobalScriptLookAndFeel();