Error in fetch results

[shyamkanani]

Traceback (most recent call last):
File "c:\Users\MyHP\Desktop\mail\demo.py", line 16, in
results = service.users().labels().list(userId='me').execute()
File "C:\Users\MyHP\AppData\Local\Programs\Python\Python36\lib\site-packages\googleapiclient_helpers.py", line 130, in positional_wrapper
return wrapped(*args, **kwargs)
File "C:\Users\MyHP\AppData\Local\Programs\Python\Python36\lib\site-packages\googleapiclient\http.py", line 842, in execute
raise HttpError(resp, content, uri=self.uri)
googleapiclient.errors.HttpError: <HttpError 403 when requesting https://www.googleapis.com/gmail/v1/users/me/labels?alt=json returned "Project 725026510391 is not found and cannot be used for API calls. If it is recently created, enable Gmail API by visiting https://console.developers.google.com/apis/api/gmail.googleapis.com/overview?project=725026510391 then retry. If you enabled this API recently, wait a few minutes for the action to propagate to our systems and retry.">