curl --request POST \
  --url https://sandbox.hurdlr.com/rest/v5/investments/gains \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: */*' \
  --data '
{
  "gains": [
    {
      "date": "2022-01-04",
      "amount": 50.01,
      "id": 123,
      "description": "<string>",
      "externalId": "<string>"
    }
  ]
}
'

[
  {
    "errors": {
      "fieldErrors": {},
      "globalErrors": [
        {
          "errorMessage": "<string>"
        }
      ]
    },
    "id": "<string>",
    "webhook": {
      "userId": "<string>",
      "accountantUserId": "<string>"
    }
  }
]