const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

fetch('https://api.paddle.com/notifications/{notification_id}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "data": {
    "id": "ntf_01hvg8ykjrcdr4jvv9rqcbkhfa",
    "type": "address.created",
    "status": "failed",
    "payload": {
      "data": {
        "id": "add_01hvg8yk4s1aqa37kxspd51bwg",
        "city": null,
        "region": null,
        "status": "active",
        "created_at": "2024-04-15T07:01:11.449Z",
        "first_line": null,
        "updated_at": "2024-04-15T07:01:11.449Z",
        "custom_data": null,
        "customer_id": "ctm_01gzgmxdmgkgc7p94b5kgqq82p",
        "description": null,
        "import_meta": null,
        "postal_code": "10021",
        "second_line": null,
        "country_code": "US"
      },
      "event_id": "evt_01hvg8ykgj5r02vvn44b8hdp8d",
      "event_type": "address.created",
      "occurred_at": "2024-04-15T07:01:11.826666Z",
      "notification_id": "ntf_01hvg8ykjrcdr4jvv9rqcbkhfa"
    },
    "occurred_at": "2024-04-15T07:01:11.826666Z",
    "delivered_at": null,
    "replayed_at": null,
    "origin": "event",
    "last_attempt_at": "2024-04-15T07:19:56.553479Z",
    "retry_at": null,
    "times_attempted": 10,
    "notification_setting_id": "ntfset_01hv6scjn6ex5bej5bdy4w9ax3"
  },
  "meta": {
    "request_id": "50aa6efc-5c11-47f4-8a7a-d13d1ffd85f2"
  }
}