JSFiddle - React, Tailwind, and code Playground

HTML

<div class="ez-checkbox">
     <input type="checkbox" name="mybox" id="mybox" value="test" onclick="nocheck( this );" class="ez-hide" />
</div>

JavaScript

var user = { premium : false };
function nocheck(elem) {
    
    var newValue = elem.checked;
    if(!user.premium) {        	               	   
		alert("not allowed");
        elem.checked = !newValue;
    } else {
        alert(" allowed ");
    }
   
};