JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container"><h1>Add-ons</h1>
<input type="checkbox" name="ch1" value="10" id="qr1" />Add-on Number 1 - 10 QR <br />
<input type="checkbox" name="ch1" value="20" id="qr1" />Add-on Number 2 - 20 QR <br />
<input type="checkbox" name="ch1" value="40" id="qr1" />Add-on Number 3 - 40 QR <br />
<input type="checkbox" name="ch1" value="60" id="qr1" />Add-on Number 4 - 60 QR <br />
</div>

<div> I want more add-ons
<select id="more" name="more">
    <option value="0 QR">0</option>
    <option value="30 QR">1</option>
    <option value="50 QR">2</option>
    <option value="100 QR">3</option>
</select>
<span id="span"></span>
 User total usage: <span id="usertotal"> </span>

JavaScript

$('input:checkbox').change(function(){ 
var tot=0;
$('input:checkbox:checked').each(function(){
tot+=parseInt($(this).val());
});
     tot+=parseInt($('#more').val());
$('#usertotal').html(tot)
});
     
     $('#more').change(function(){
      $('input:checkbox').trigger('change');
     });