Get an order by reference

{
  "data": {
    "id": 0,
    "reference": "string",
    "enterprise_id": 0,
    "user_id": 0,
    "opportunity_id": 0,
    "date_limit": "2019-08-24",
    "comments": "string",
    "extra_fields": {},
    "states": [
      {
        "id": 0,
        "state": 0,
        "amount": 0.1,
        "created_at": "2019-08-24T14:15:22Z"
      }
    ],
    "products": [
      {
        "id": 0,
        "reference": "string",
        "name": "string",
        "pivot": {
          "cost": 0,
          "price": 0,
          "discount": 0,
          "quantity": 0,
          "comment": "string"
        }
      }
    ],
    "created_at": "2019-08-24T14:15:22Z",
    "updated_at": "2019-08-24T14:15:22Z"
  }
}