curl --request PUT \
  --url https://api.gospott.com/custom-attributes/client-contacts/{id}/values/_bulk \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "attributes": [
    {
      "attributeDefinitionId": "<string>",
      "value": {
        "viewType": "customText",
        "text": "<string>"
      }
    }
  ]
}
'

{
  "status": 0,
  "message": "At least one attribute is required",
  "requestId": "<string>",
  "statusCode": 400,
  "error": "Bad Request"
}