JSFiddle - React, Tailwind, and code Playground

by Dmitry Rekun

HTML

<input id="cal21" type="checkbox" name="calendar_id[]" value="21">           
<input id="cb21" type="checkbox" onclick="Joomla.isChecked(this.checked);" value="21" name="cid[]">

JavaScript

$("input[name = 'cid[]']").on( "click", function() {
  $('#cal'+this.value).attr('checked', 'checked');
});