https://blog.wongcw.com/2020/01/30/libreoffice-6-4%e7%99%bc%e5%b8%83%ef%bc%9a%e6%8f%90%e5%8d%87%e6%80%a7%e8%83%bd%e5%84%aa%e5%8c%96%e5%b9%ab%e5%8a%a9%e5%bc%95%e5%85%a5qr-code%e7%94%9f%e6%88%90%e5%99%a8/