curl --request POST \
  --url https://{deployment}/api/v1/notion/bulk-upsert \
  --header 'Content-Type: application/json' \
  --header 'X-API-KEY: <api-key>' \
  --header 'X-Notion-Token: <api-key>' \
  --data '
{
  "notion_id": "26f...",
  "lookup_properties": [
    "Email"
  ],
  "records": [
    {
      "Email": "a@b.com",
      "Name": "A"
    }
  ]
}
'

{
  "success": true,
  "total": 123,
  "inserted": 123,
  "updated": 123,
  "failed": 123,
  "results": [
    {
      "index": 123,
      "success": true,
      "page_id": "<string>",
      "data": {},
      "error": "<string>",
      "error_code": "<string>"
    }
  ],
  "failed_data": [
    {}
  ],
  "error_message": "<string>"
}