how to disable the browser back button in javascript.

how to disable the browser back button in javascript.

Dont!

You can't, and you shouldn't.

every other approach / alternative will only cause really bad user
engagement.

Put This script on head of your page and change 'pagename' to your page
name.
but anyway , here is a trick :

<script type = "text/javascript" >
    history.pushState(null, null, 'pagename');
    window.addEventListener('popstate', function(event) {
    history.pushState(null, null, 'pagename');
    });
    </script>