code: async function runSample() {
    const res = await gmail.users.watch({
      userId: 'me',
      requestBody: {
        // Replace with `projects/${PROJECT_ID}/topics/${TOPIC_NAME}`
        topicName: `projects/el-gato/topics/gmail`,
      },
    });
    console.log(res.data);
    return res.data;
  }
docs: NOTE: Before using this API, you need to do a few things.
  1. Create a new Pub/Sub topic.  You can use the command:
  gcloud pubsub topics create gmail
  2. Go to the Cloud Developer Console, and give the gmail
  service account gmail-api-push@system.gserviceaccount.com
  Pub/Sub Publisher rights to your newly created topic.
  https://console.cloud.google.com/cloudpubsub/topicList?project=${PROJECT_NAME}