PowerBi dataset refresh via API

Hi,

I am trying to write Python code to trigger PowerBi dataset refresh. I have followed the online resources and written the below code. But I am getting a "Resource 403" error when I run this script.

import requests, json
import urllib

token_url = "https://login.microsoftonline.com/<tenant id>/oauth2/token"

test_api_url = "https://api.powerbi.com/v1.0/myorg/datasets/<dataset id>/refreshes"

client_id = 'client id'
client_secret = 'client secret'

data = {'grant_type': 'client_credentials'}

access_token_response = requests.post(token_url, data=data, verify=False, allow_redirects=False, auth=(client_id, client_secret))

print(access_token_response.text)

tokens = json.loads(access_token_response.text)

api_call_headers = {'Authorization': 'Bearer ' + tokens['access_token'], 'Content-Length': '1025'}
api_call_response = requests.post(test_api_url, headers=api_call_headers)

print (api_call_response)

Could you please help me with this?

Thanks in advance.