curl --request GET \
  --url https://api.voltview.co.uk/v1/sites/{siteId}/cost \
  --header 'x-api-key: <api-key>'

{
  "siteId": "<string>",
  "period": "<string>",
  "totalCost": 123,
  "energyCost": 123,
  "standingCharges": 123,
  "data": [
    {
      "timestamp": "2023-11-07T05:31:56Z",
      "cost": 123,
      "consumption": 123
    }
  ]
}