JSFiddle - React, Tailwind, and code Playground

HTML

<form id="form">
    <input type="checkbox" id="cb1"/> <label for="cb1">Checkbox 1</label>
    <input type="checkbox" id="cb2"/> <label for="cb2">Checkbox 2</label>
    <input type="checkbox" id="cb3"/> <label for="cb3">Checkbox 3</label>
    <input type="checkbox" id="cb4"/> <label for="cb4">Checkbox 4</label>
    <button id="delete" class="hidden">Удалить отмеченные</button>
</form>

CSS

.hidden { display: none; }

JavaScript

$('#form input:checkbox').change(function () {
    $('#delete').toggle($('#form input:checkbox:checked').length>0);
});