JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" class="input value1">
<input type="text" class="input value2">
<input type="text" disabled="disabled" id="result">

JavaScript

$(document).ready(function(){
    $(".input").keyup(function(){
          var val1 = +$(".value1").val();
          var val2 = +$(".value2").val();
          $("#result").val(val1+val2);
   });
});