Add indicators as any other module - general module loading documentation is also available on the main page of the Highcharts Angular wrapper GitHub repository.
After Highcharts is imported using Highstock (as a core like in the code snippet below, or as a Highcharts + stock module) use
import and initialize core indicator module first and all needed indicators next (e.g. ZigZag indicator) on the Highcharts variable.
import * as Highcharts from "highcharts/highstock"; const IndicatorsCore = require("highcharts/indicators/indicators"); IndicatorsCore(Highcharts); const IndicatorZigZag = require("highcharts/indicators/zigzag"); IndicatorZigZag(Highcharts);