JSFiddle - React, Tailwind, and code Playground

JavaScript

var timeout;
$(window).on('beforeunload', function (){
    timeout = setTimeout(function() {
        alert('You stayed');
    }, 1000);
    return "You save some unsaved data, Do you want to leave?";
});

function noTimeout() {
    alert("You're leaving!");
    clearTimeout(timeout);
}
    
window.unload = noTimeout;