curl --request POST \
  --url https://api.returnshelper.com/uat/user/api/ReturnShipment/createReturnShipment \
  --header 'Content-Type: application/json' \
  --header 'x-rr-apikey: <api-key>' \
  --header 'x-rr-apitoken: <api-key>' \
  --data '
{
  "serviceTypeCode": "fedex_ground",
  "orderTitle": "Return Label Title",
  "orderNumber": "123123",
  "totalValueCurrency": "usd",
  "shipment": {
    "shipToWarehouseId": 2,
    "boxType": "cus",
    "sellerReferenceNumber": "<string>",
    "shipFrom": {
      "country": "usa",
      "contactName": "Your name",
      "phone": "15622708183",
      "email": "user@example.com",
      "fax": "<string>",
      "street1": "Some address line 1",
      "street2": "Some address line 2",
      "street3": "<string>",
      "state": "tx",
      "city": "Houston",
      "postalCode": "77235"
    },
    "parcel": {
      "weight": 10.5,
      "weightUnit": "g",
      "length": 10,
      "width": 10,
      "height": 10,
      "dimensionUnit": "cm",
      "items": [
        {
          "description": "Test item",
          "weight": 10.5,
          "value": 100,
          "weightUom": "g",
          "valueCurrencyCode": "usd"
        }
      ]
    },
    "customFieldMap": {}
  },
  "totalValue": 100,
  "sellerReferenceNumber": "<string>",
  "remarks": "<string>"
}
'