JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-1.12.0.min.js"></script>
<input type='text' id='tb' value='ABC' data-initial='ABC' maxlength='10' />

JavaScript

$(document).ready(function() {
	$("#tb").on("keyup", function() {
  	var value = $(this).val();
  	$(this).val($(this).data("initial") + value.substring(3));
  });
});