Appointments Plugin API error

I have been receiving this error after following the instructions for installing the API, any suggestions to remedy would be GREATLY appreciated :slight_smile:

[Appointments+] The following error has been reported by Google Calendar API:

exception ‘Google_ServiceException’ with message ‘Error calling POST (404) Not Found’ in /home/content/53/8314453/html/

Recommendation: Please double check your settings.

url is: