Facing an issue with Microsoft Graph apis on accessing the one note content using site_id

I having these graph apis access

I am using below code to get the one notes content using site_id

import requests
from env import *

class SharePointNotebookLister:
    def __init__(self, tenant_id, client_id, client_secret):
        self.tenant_id = tenant_id
        self.client_id = client_id
        self.client_secret = client_secret
        self.access_token = None

    def get_access_token(self):
        """Get access token using MSAL"""
        base_url = f"https://login.microsoftonline.com/{self.tenant_id}/oauth2/v2.0/token"
        headers = {'Content-Type': 'application/x-www-form-urlencoded'}
        body = {
                'grant_type': 'client_credentials',
                'client_id': self.client_id,
                'client_secret': self.client_secret,
                'scope': 'https://graph.microsoft.com/.default'
            }
        response = requests.post(base_url, headers=headers, data=body)
        self.access_token = response.json().get('access_token')
        return self.access_token

    def list_site_notebooks(self, site_id=None):
        """List all notebooks in a SharePoint site"""
        if not self.access_token:
            self.get_access_token()

        headers = {
            'Authorization': f'Bearer {self.access_token}',
            'Content-Type': 'application/json'
        }

        # If site_id is not provided, get the root site
        
        if not site_id:
            
            site_relative_url = f"domain:/sites/site_name"
            site_response = requests.get(
                f'https://graph.microsoft.com/v1.0/sites/{site_relative_url}',
                headers=headers
            )
            site_response.raise_for_status()
            site_id = site_response.json()['id']

        # Get all notebooks in the site
        notebooks_url = f'https://graph.microsoft.com/v1.0/sites/{site_id}/onenote/notebooks'
        response = requests.get(notebooks_url, headers=headers)
        response.raise_for_status()

        notebooks = response.json().get('value', [])
        return notebooks

    def get_notebook_sections(self, notebook_id):
        """Get all sections in a specific notebook"""
        if not self.access_token:
            self.get_access_token()

        headers = {
            'Authorization': f'Bearer {self.access_token}',
            'Content-Type': 'application/json'
        }

        sections_url = f'https://graph.microsoft.com/v1.0/sites/{notebook_id}/onenote/notebooks/sections'
        response = requests.get(sections_url, headers=headers)
        response.raise_for_status()

        sections = response.json().get('value', [])
        return sections

# Usage example
if __name__ == "__main__":

    try:
        # Initialize the notebook lister
        lister = SharePointNotebookLister(tenant_id, client_id, client_secret)
        access_token = lister.get_access_token()
        # List all notebooks
        notebooks = lister.list_site_notebooks()

        print("\nFound notebooks:")
        for notebook in notebooks:
            print(f"\nNotebook: {notebook['displayName']}")
            print(f"ID: {notebook['id']}")
            print(f"Created: {notebook['createdDateTime']}")
            print(f"Last Modified: {notebook['lastModifiedDateTime']}")

            # Get sections for each notebook
            sections = lister.get_notebook_sections(notebook['id'])
            if sections:
                print("\nSections:")
                for section in sections:
                    print(f"- {section['displayName']}")

    except Exception as e:
        print(f"Error: {str(e)}")

After running this code it is giving me below error
Error: 401 Client Error: Unauthorized for url: https://graph.microsoft.com/v1.0/sites/sparkflowsai.sharepoint.com,a783db0b-51cb-43 .....

Do I need any other permission to get the access of one note's content using site id. I have all my notebooks inisde that sharepoint sites.

The sites url I am using: {sub_domain}.sharepoint.com:/sites/{site_name}

Can anyone please help me here?