Get an order via order number

{
  "deliveryAddress": {
    "addition": "Hinterm Haus",
    "city": "Musterstadt",
    "countryCode": "DEU",
    "email": "test@example.com",
    "firstName": "Max",
    "houseNumber": "17",
    "lastName": "Mustermann",
    "phoneNumber": "0491234567890",
    "salutation": "MR",
    "street": "Musterstraße",
    "zipCode": "12345"
  },
  "initialDeliveryFees": [
    {
      "deliveryFeeAmount": {
        "amount": 15.99,
        "currency": "EUR"
      },
      "name": "DELIVERY_FEE_STANDARD",
      "positionItemIds": [
        "1cdef481-683c-4a4c-bf42-fa7f6bb00933",
        "09532b32-6f4e-4277-988b-f5f721ca13c4"
      ],
      "vatRate": 19
    }
  ],
  "initialDiscounts": [
    {
      "discountAmount": {
        "amount": 15.99,
        "currency": "EUR"
      },
      "discountId": "9978",
      "discountName": "15% auf Technik",
      "name": "DISCOUNT",
      "positionItemIds": [
        "1cdef481-683c-4a4c-bf42-fa7f6bb00933",
        "09532b32-6f4e-4277-988b-f5f721ca13c4"
      ],
      "vatRate": 19
    }
  ],
  "invoiceAddress": {
    "addition": "Hinterm Haus",
    "city": "Musterstadt",
    "countryCode": "DEU",
    "email": "test@example.com",
    "firstName": "Max",
    "houseNumber": "17",
    "lastName": "Mustermann",
    "phoneNumber": "0491234567890",
    "salutation": "MR",
    "street": "Musterstraße",
    "zipCode": "12345"
  },
  "links": [
    {
      "href": "/v4/orders/12345678,/v4/orders/?nextCursor=bsdjfvbkjdfv",
      "rel": "next,self,describedby"
    }
  ],
  "orderNumber": "p982bht4t29",
  "payment": {
    "paymentMethod": "INVOICE_SINGLE"
  },
  "positionItems": [
    {
      "dealId": "d36cbfd9-b7b9-44d5-96d3-052d6fd97a44",
      "dealName": "Deal der Woche 52",
      "expectedDeliveryDate": "2018-10-30T12:00:00+01:00",
      "itemValueDiscount": {
        "amount": 15.99,
        "currency": "EUR"
      },
      "itemValueGrossPrice": {
        "amount": 15.99,
        "currency": "EUR"
      },
      "itemValueReducedGrossPrice": {
        "amount": 15.99,
        "currency": "EUR"
      },
      "positionItemId": "7323981b-14b4-7123-7812-ac783d98132c",
      "product": {
        "articleNumber": "S000003AXQU",
        "dimensions": [
          {
            "displayName": "Farbe",
            "type": "color",
            "value": "schwarz"
          }
        ],
        "ean": "233232323",
        "productTitle": "Black T-Shirt",
        "sku": "13033",
        "vatRate": 19
      },
      "returnAcceptedByMarketplace": true,
      "trackingInfo": {
        "carrier": "DHL",
        "trackingNumber": "H1234567890123456789"
      }
    }
  ],
  "salesOrderId": "9864623c-42a4-4892-9270-cd733d32362e"
}