Get Notion page content

I'm trying to retrieve the content of my Notion workspace using the Notion API. I created a new integration, made sure pages I'm trying to access are connected to the integration and executed the following code:

class NotionClient:
    def __init__(self, access_token):
        self.access_token = access_token
        self.headers = {
            'Authorization': f"Bearer {self.access_token}",
            'Content-Type': 'application/json',
            'Notion-Version': '2022-06-28'
        }
        self.session = requests.Session()
        self.session.headers.update(self.headers)
        self.NOTION_BASE_URL = 'https://api.notion.com/v1/'

    def query_workspace(self, page_id):
        page_url = urljoin(self.NOTION_BASE_URL, f"blocks/{page_id}/children?page_size=100")
        return self.session.post(page_url)  


access_token = "secret_..."
page_id = "..."

notion = NotionClient(access_token)
response = notion.query_workspace(page_id)
print(response.json())  

This gives the 401 error code and returns the following error:

{"object":      "error",
"status":       401,
"code":         "unauthorized",
"message":      "API token is invalid.",
"request_id":   "433f38d5-d281-4b88-9bb5-875d4d0b0d8b"
}

I'm not sure what is the problem here, I'm certain my API key is valid and has the required scope and this should be the current Notion version as far as i know, but i could be wrong.

You have to use get() instead of post(). That's all.

return self.session.get(page_url)