JSFiddle - React, Tailwind, and code Playground

HTML

<form id="testform">
    <input type="checkbox" name="test_checkbox[0]" id="test" checked="checked" value="true"/>
    <input type="checkbox" name="test_checkbox[1]" id="test1" checked="checked" value="true"/>
<span>click</span>
</form>

JavaScript

$('span').click(function() {
    var formDate = $('#testform').serialize();
    console.log(formDate);
})