public function getAuthorizationURL()
    {
        $url = Config::inst()->get(self::class, 'AuthorizationUrl');
        $params = [
            'client_id' => $this->client_id,
            'redirect_uri' => $this->getRedirectURL(),
            'response_type' => "code",
            'scope' => $this->scopes,
        ];

        return $url . "?" . http_build_query($params);
    }