curl --request GET \
  --url https://thalamus.nerds.nl/api/v1/reference/subcategory \
  --header 'Authorization: Bearer <token>'

{
  "success": true,
  "data": [
    {
      "external_id": "<string>",
      "value": "<string>",
      "label": "<string>",
      "sort_order": 123
    }
  ]
}