JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" name="newsletter" value="Hourly" checked="checked">  <input   type="checkbox" name="newsletter" value="Daily">
<input type="checkbox" name="newsletter" value="Weekly" checked>
<input type="checkbox" name="newsletter" value="Monthly">
<input type="checkbox" name="newsletter" value="Yearly">
<br><button id="selectall">Select All</button>

JavaScript

var selectall = function() {
     $("input[type=checkbox]").prop("checked","true");    
};
$("#selectall").on("click", selectall );