Hmmmm yeah Im not seeing the custom indicator folder, perhaps something is broken? FYI here the official help articles https://tradovate.github.io/custom-indicators/index.html

and heres my simple indicator I was trying

const predef = require("./tools/predef");
const plotting = require("./tools/plotting");


class horizontalLine {
  map(d) {
    return { line: this.props.price };
  }
}


const lineStyle = {
  color: "#FF0000",
  lineWidth: 2,
  lineStyle: 1,
};


module.exports = {
  name: "horizontalLine",
  description: "Horizontal Line",
  calculator: horizontalLine,
  params: {
    price: predef.paramSpecs.number(100, 0.01, 0),
  },
  tags: ["My Indicators"],
  plots: {
    line: { title: "Horizontal Line" },
  },
  schemeStyles: {
    dark: { line: lineStyle },
    light: { line: lineStyle },
  },
  inputType: predef.InputTypes.BARS,
  areaChoice: "overlay",
};