JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" name="mybox" id="mybox" value="test" onclick="noCheck(event)" />

JavaScript

var user = { premium : true };
function noCheck (e) {
    e = e || window.event;
    if( !user.premium ) {
        e.preventDefault();
        alert("not allowed");
    };
};