public static function authorizeUrl($params = null)
    {
        if (!$params) {
            $params = array();
        }

        $params['client_id'] = self::_getConnectParam('client_id', $params);
        $params['redirect_uri'] = self::_getConnectParam('redirect_uri', $params);
        if (!array_key_exists('response_type', $params)) {
            $params['response_type'] = 'code';
        }
        $query = Util\Util::urlEncode($params);

        return Sumup::$connectBase . '/authorize?' . $query;
    }