JSFiddle - React, Tailwind, and code Playground

JavaScript

var activeInput=true;

    window.addEventListener('beforeunload', checkNow);

    function checkNow(e) {
            if (activeInput === false) return true;
            var message = "Are you sure you want to leave this page? Ensure you save any changes.";
            e.returnValue = message;
            return message;
    }