JSFiddle - React, Tailwind, and code Playground
by Artur Soul
HTML
<label>
<div class="checker">
<span class=""><input type="checkbox" name="UnitTag[197][tagId]" value="197"></span>
</div>
Окончание на грудь (доп.)
</label>
JavaScript
$('label').on('change', function(){
let input = $(this).find('input[type=checkbox]');
if(input.prop('checked') === false){
alert('yes');
} else {
alert('nope');
}
});