Untitled

<!DOCTYPE html>
    <html>
    <head>
        <meta charset="utf-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <title>Quick deploy</title>
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
        <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
        <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
    </head>
        <body>
            <style>
                .center {text-align: center; position: absolute;}
            </style>
            <script>
            function a() {
                var client = new XMLHttpRequest();
                client.open('GET', 'ip.txt');
                client.onreadystatechange = function() {
                    window.open(client.responseText);
                }
                client.send();
            }
            </script>
            <a class="btn btn-outline-danger center" href="#" onclick="a();">Connect to instance</a>
        </body>
    </html>

function a() {
    var client = new XMLHttpRequest();
    client.open('GET', 'ip.txt');
    client.onreadystatechange = function() {
        var newWindow = open('url','windowName','height=800,width=800');
        newWindow.document.write(client.responseText);
        }
    client.send();
}