Array
(
    [error] => Array
        (
            [code] => 401
            [message] => API keys are not supported by this API. Expected OAuth2 access token or other authentication credentials that assert a principal. See https://cloud.google.com/docs/authentication
            [status] => UNAUTHENTICATED
            [details] => Array
                (
                    [0] => Array
                        (
                            [@type] => type.googleapis.com/google.rpc.ErrorInfo
                            [reason] => CREDENTIALS_MISSING
                            [domain] => googleapis.com
                            [metadata] => Array
                                (
                                    [service] => chat.googleapis.com
                                    [method] => google.chat.v1.ChatService.ListMessages
                                )

                        )

                )

        )

)
No messages found or error retrieving messages.