how to generate token in synapse notebook using identity

Question

how to generate token in synapse notebook using identity.
Why below code is not working?

import requests


def get_token_for_risk_api():
    resource = "https://xxxxxx"
    user_managed_client_id = "xxxx"
    api_version = "2019-08-01"
    # Construct the URL for token retrieval
    endpoint = "http://169.254.169.254/metadata/identity/oauth2/token"
    url = f"{endpoint}?api-version={api_version}&resource={resource}&client_id={user_managed_client_id}"
    
    
    # Construct headers (including 'Metadata: true' header)
    headers = {
        'Metadata': 'true'
    }
    
    try:
        # Send GET request to Azure IMDS endpoint
        response = requests.get(url, headers=headers)
        response.raise_for_status()  # Raise an exception for 4xx or 5xx responses
        
        # Parse JSON response and extract access token
        token_response = response.json()
        risk_api_token = token_response['access_token']
        
        return risk_api_token
    
    except requests.exceptions.RequestException as e:
        print(f"Error occurred while obtaining access token: {e}")
        return None

# Example usage:
if __name__ == "__main__":
    token = get_token_for_risk_api()
    if token:
        print(f"Received access token: {token}")
    else:
        print("Failed to obtain access token.")