How to refresh another page using javascript without opening the same page in a new tab

I got the idea from a previous Question , here they used window Object Reference to reload the popup window, but for me it wont work, because, the parent window and child window runs in 2 different ports. So using the same trick, what i did is :

HTML:

<a onclick="openNewTab()">app2</a>

<a onclick="refreshExistingTab()">Refresh</a>

JS:

<script>

    var childWindow = "";
    var newTabUrl="http://localhost:8081/app/home";

    function openNewTab(){
        childWindow = window.open(newTabUrl);
    }

    function refreshExistingTab(){
        childWindow.location.href=newTabUrl;
    }

</script>

refreshExistingTab() this instend of refreshExistingTab

take a look at https://developer.mozilla.org/en-US/docs/Web/API/Window.open basically if you do window.open and specify a window name it will overwrite that window with the url you provided. so if you open the page each time with same window name, it should overwrite it each time you do it again from that other page.