curl --request GET \
  --url http://localhost:3000/v1/partner/categories/{id}/subcategories

{
  "subcategories": [
    {
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "name": "<string>",
      "parent_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "level": 123
    }
  ]
}