How to use the datadog-metrics.init function in datadog-metrics

timestamp
    );
  },
  gauge: (key: string, value: number, tags?: Tags, timestamp?: number) => {
    log('gauge', key, value, tags, timestamp);
  },
};
if (
  !process.env.DATADOG_API_KEY ||
  process.env.DATADOG_API_KEY === 'undefined'
) {
  console.warn('No DATADOG_API_KEY provided, not tracking metrics.');
} else {
  console.warn('Tracking metrics to DataDog.');
  const metrics = require('datadog-metrics');
  metrics.init({
    defaultTags: [
      `server:${process.env.SENTRY_NAME || 'unknown_server'}`,
      `hostname: ${os.hostname() || 'unknown_instance_hostname'}`,
    ],
  });

  // This is necessary for express-hot-shots to work
  const handleObjectTags = method => {
    const original = metrics[method];
    metrics[method] = (key, val, tags, timestamp) => {
      return original.call(
        metrics,
        key,
        val,
        Array.isArray(tags) ? tags : stringify(tags),
        timestamp

//   "target": "https://shop.nordstrom.com",
  //   "mobile": false
  // }
  console.log(event)

  // Flags for launching lighhouse
  // ref: https://github.com/GoogleChrome/lighthouse/blob/HEAD/docs/configuration.md
  const flags = {
    disableDeviceEmulation: !event.mobile || true,
    disableCpuThrottling: true,
    disableNetworkThrottling: true
  }

  // Initialize datadog metrics collection
  // ref: https://github.com/dbader/node-datadog-metrics#initialization
  metrics.init({
    host: 'host',
    prefix: 'prefix.',
    flushIntervalSeconds: 0,
    apiKey: process.env.DATADOG_API_KEY,
    appKey: process.env.DATADOG_APP_KEY,
    defaultTags: [ `audit-target:${event.target}` ]
  })

  // Attach lighthouse to chrome and run an audit.
  // ref: https://github.com/GoogleChrome/lighthouse/blob/master/docs/readme.md#using-programmatically
  lighthouse(event.target, flags).then(function(results) {
    // Increment the lighthouse counter
    metrics.increment('lighthouse.invoke')

    // Get total page load time metric
    // push metric to datadog, ref: https://github.com/dbader/node-datadog-metrics#gauges