curl --request POST \
  --url https://api.hubapi.com/marketing/v3/marketing-events/batch/update \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "inputs": [
    {
      "startDateTime": "2023-11-07T05:31:56Z",
      "customProperties": [
        {
          "sourceId": "",
          "selectedByUser": false,
          "sourceLabel": "",
          "sourceUpstreamDeployable": "<string>",
          "source": "",
          "updatedByUserId": 123,
          "persistenceTimestamp": 123,
          "sourceMetadata": "",
          "dataSensitivity": "",
          "sourceVid": "",
          "unit": "",
          "requestId": "",
          "isEncrypted": false,
          "name": "",
          "useTimestampAsPersistenceTimestamp": true,
          "value": "",
          "selectedByUserTimestamp": 123,
          "timestamp": 123,
          "isLargeValue": true
        }
      ],
      "eventCancelled": true,
      "eventOrganizer": "<string>",
      "eventUrl": "<string>",
      "eventDescription": "<string>",
      "eventName": "<string>",
      "eventType": "<string>",
      "endDateTime": "2023-11-07T05:31:56Z",
      "objectId": "<string>"
    }
  ]
}'