JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" /><br />
<input type="submit" value="submit"/>

JavaScript

$(document).ready(function() {    
    /* Must only work for input fields in the iframe itself !! */
    $('input').focus(function(){
        alert("Hello");
        $(parent.document).find('input').val('Value set from child iframe');
        $(parent.document).changeStyle();
    });
    /* End for Iframe */
    /* Must I place the script on the page of the Iframe? */
});