import Courier from '@trycourier/courier';

const client = new Courier({
  apiKey: process.env['COURIER_API_KEY'], // This is the default and can be omitted
});

const preference = await client.users.preferences.retrieve('user_id');

console.log(preference.items);

{
  "paging": {
    "cursor": "MTpFWUNFRkRRN0c1WERTRTU2",
    "more": true
  },
  "items": [
    {
      "custom_routing": [
        "direct_message"
      ],
      "default_status": "OPTED_IN",
      "has_custom_routing": true,
      "status": "OPTED_IN",
      "topic_id": "PT91W47CKEMP6PW0RYVN3F08F2YE",
      "topic_name": "string"
    }
  ]
}