index.html

<!DOCTYPE HTML>
<html lang="en-US">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="refresh" content="0; url=index_en.html">
        <script type="text/javascript">
            window.location.href = "index_en.html"
        </script>
        <title>Page Redirection</title>
    </head>
    <body>
        If you are not redirected automatically towards https://open-plan-tool.org/index_en.html, follow this <a href='index_en.html'>link</a>, or copy-paste the url in your favorite browser.
    </body>
</html>