Remove subpage after post

After my form posts, the page refreshes. However I can't seem how to return back to localhost:8080, rather than what is seen in the picture below. I would like after the page is done posting to return to http://localhost:8080/Manager.

Manager Access HTML

<div class='form-group'>
    <form id="signin-form" method="POST" action="/upcset">
        <input name="AcceptedUPC" type="text" autofocus autocomplete="off">
        <button id="upcSubmit" type="submit">Submit</button>
    </form>
</div>

Manager Access JS

$('document').ready(function(){
    $.get('upcs', (data) => {
        data.forEach(element => {
            $('#upcList').append('<li>' + element.AcceptedUPC + '</li>');
            console.log('<li>' + element.AcceptedUPC + '</li>');
        });
    });
});

Server.js

app.get('/upcs', (req,res) => {
    //get current list from DB
});

app.post('/upcset', urlencodedParser, (req,res) => {
    var acceptedupc = req.body.AcceptedUPC;
    //insert into DB etc
    res.sendFile(path.join(__dirname + '/ManagerAccess.html'));
});