public static function getLaunchContent($endpoint, $debug=false)
    {
            $info = LTIX::getKeySecretForLaunch($endpoint);
            if ( $info === false ) {
                return '<p style="color:red">Unable to load key/secret for '.htmlentities($endpoint)."</p>\n";
            }
            $key = $info['key'];
            $secret = self::decrypt_secret($info['secret']);

            $parms = LTIX::getLaunchData();

            $parms = LTI::signParameters($parms, $endpoint, "POST", $key, $secret, "Button");

            $content = LTI::postLaunchHTML($parms, $endpoint, false);
            return $content;
    }