JSFiddle - React, Tailwind, and code Playground
HTML
<input type="text" id="textOne" onkeyup="clone();" />
<input type="text" id="textTwo" />
JavaScript
function clone() {
$("#textTwo").val($("#textOne").val());
}
<input type="text" id="textOne" onkeyup="clone();" />
<input type="text" id="textTwo" />
function clone() {
$("#textTwo").val($("#textOne").val());
}