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

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

{
  "data": {
    "id": "ntfset_01gkpjp8bkm3tm53kdgkx6sms7",
    "description": "Slack notifications",
    "type": "url",
    "destination": "https://hooks.slack.com/example",
    "active": true,
    "api_version": 1,
    "include_sensitive_fields": false,
    "traffic_source": "all",
    "subscribed_events": [
      {
        "name": "transaction.billed",
        "description": "Occurs when a transaction is billed.",
        "group": "Transaction",
        "available_versions": [
          1
        ]
      },
      {
        "name": "transaction.canceled",
        "description": "Occurs when a transaction is canceled.",
        "group": "Transaction",
        "available_versions": [
          1
        ]
      },
      {
        "name": "transaction.completed",
        "description": "Occurs when a transaction is completed.",
        "group": "Transaction",
        "available_versions": [
          1
        ]
      },
      {
        "name": "transaction.created",
        "description": "Occurs when a transaction is created.",
        "group": "Transaction",
        "available_versions": [
          1
        ]
      },
      {
        "name": "transaction.payment_failed",
        "description": "Occurs when a payment fails for a transaction.",
        "group": "Transaction",
        "available_versions": [
          1
        ]
      },
      {
        "name": "transaction.ready",
        "description": "Occurs when a transaction is ready.",
        "group": "Transaction",
        "available_versions": [
          1
        ]
      },
      {
        "name": "transaction.updated",
        "description": "Occurs when a transaction is updated.",
        "group": "Transaction",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.activated",
        "description": "Occurs when a subscription is activated.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.canceled",
        "description": "Occurs when a subscription is canceled.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.created",
        "description": "Occurs when a subscription is created.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.past_due",
        "description": "Occurs when a subscription is past due.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.paused",
        "description": "Occurs when a subscription is paused.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.resumed",
        "description": "Occurs when a subscription is resumed.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.trialing",
        "description": "Occurs when a subscription is trialing.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      },
      {
        "name": "subscription.updated",
        "description": "Occurs when a subscription is updated.",
        "group": "Subscription",
        "available_versions": [
          1
        ]
      }
    ],
    "endpoint_secret_key": "pdl_ntfset_01gkpjp8bkm3tm53kdgkx6sms7_6h3qd3uFSi9YCD3OLYAShQI90XTI5vEI"
  },
  "meta": {
    "request_id": "c45900af-c48b-46cd-a917-126e433feb21"
  }
}