Basic

const config = { type: 'line', data, options: { plugins: { annotation: { annotations: { annotation1, annotation2, annotation3 } } } } };

const config = {
  type: 'line',
  data,
  options: {
    plugins: {
      annotation: {
        annotations: {
          annotation1,
          annotation2,
          annotation3
        }
      }
    }
  }
};

const annotation1 = { type: 'point', backgroundColor: 'rgba(0,255,255,0.4)', borderColor: 'black', borderWidth: 3, scaleID: 'y', xValue: (ctx) => value(ctx, 0, 2, 'x'), yValue: (ctx) => value(ctx, 0, 2, 'y') };

const annotation1 = {
  type: 'point',
  backgroundColor: 'rgba(0,255,255,0.4)',
  borderColor: 'black',
  borderWidth: 3,
  scaleID: 'y',
  xValue: (ctx) => value(ctx, 0, 2, 'x'),
  yValue: (ctx) => value(ctx, 0, 2, 'y')
};

const annotation2 = { type: 'point', backgroundColor: 'transparent', borderColor: 'red', borderWidth: 5, pointStyle: 'triangle', radius: 25, scaleID: 'y', xValue: (ctx) => value(ctx, 1, 4, 'x'), yValue: (ctx) => value(ctx, 1, 4, 'y') };

const annotation2 = {
  type: 'point',
  backgroundColor: 'transparent',
  borderColor: 'red',
  borderWidth: 5,
  pointStyle: 'triangle',
  radius: 25,
  scaleID: 'y',
  xValue: (ctx) => value(ctx, 1, 4, 'x'),
  yValue: (ctx) => value(ctx, 1, 4, 'y')
};

const annotation3 = { type: 'point', borderColor: 'orange', borderWidth: 3, drawTime: 'beforeDraw', pointStyle: 'star', radius: 25, scaleID: 'y', xValue: (ctx) => value(ctx, 1, 6, 'x'), yValue: (ctx) => value(ctx, 1, 6, 'y') };

const annotation3 = {
  type: 'point',
  borderColor: 'orange',
  borderWidth: 3,
  drawTime: 'beforeDraw',
  pointStyle: 'star',
  radius: 25,
  scaleID: 'y',
  xValue: (ctx) => value(ctx, 1, 6, 'x'),
  yValue: (ctx) => value(ctx, 1, 6, 'y')
};

function value(ctx, datasetIndex, index, prop) { const meta = ctx.chart.getDatasetMeta(datasetIndex); const parsed = meta.controller.getParsed(index); return parsed ? parsed[prop] : NaN; }

function value(ctx, datasetIndex, index, prop) {
  const meta = ctx.chart.getDatasetMeta(datasetIndex);
  const parsed = meta.controller.getParsed(index);
  return parsed ? parsed[prop] : NaN;
}

const DATA_COUNT = 8; const MIN = 10; const MAX = 100; Utils.srand(5); const labels = []; for (let i = 0; i < DATA_COUNT; ++i) { labels.push('' + i); } const numberCfg = {count: DATA_COUNT, min: MIN, max: MAX}; const data = { labels: labels, datasets: [{ data: Utils.numbers(numberCfg) }, { data: Utils.numbers(numberCfg) }, { data: Utils.numbers(numberCfg) }] };

const DATA_COUNT = 8;
const MIN = 10;
const MAX = 100;
Utils.srand(5);
const labels = [];
for (let i = 0; i < DATA_COUNT; ++i) {
  labels.push('' + i);
}
const numberCfg = {count: DATA_COUNT, min: MIN, max: MAX};
const data = {
  labels: labels,
  datasets: [{
    data: Utils.numbers(numberCfg)
  }, {
    data: Utils.numbers(numberCfg)
  }, {
    data: Utils.numbers(numberCfg)
  }]
};