JSFiddle - React, Tailwind, and code Playground

HTML

<div class="quantity">
    <input value=">> "><span class="output"></span>  <br>
    <input><span class="output"></span>  <br>
    <input><span class="output"></span>
</div>

<p>Note: change() will not trigger until input loses focus</p>

CSS

.output{border:1px dotted red;display:inline-block;padding:10px}

JavaScript

$('.quantity input').change(function() {
    $(this).value = ">> ";
});