ref: https://nikkie-ftnext.hatenablog.com/entry/python-notion-client-hello-world-add-page

add_notion_page.py

import os

from notion_client import Client

parent_page_id = "ID from URL (pageをintegrationにコネクト)"
notion = Client(auth=os.environ["NOTION_TOKEN"])  # integration secret

new_page = notion.pages.create(
    parent={"type": "page_id", "page_id": parent_page_id},
    properties={
        "title": {"title": [{"text": {"content": "notion-clientで作成"}}]}
    },
    children=[
        {
            "object": "block",
            "type": "paragraph",
            "paragraph": {
                "rich_text": [
                    {
                        "type": "text",
                        "text": {"content": "Hello World\nこんにちは"},
                    }
                ]
            },
        }
    ],
)