JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox">
<object class="iframe" type="text/html" id="download">what</object>

CSS

object {
    font-family: sans-serif;
    font-weight: bold;
    text-decoration: none;
}

object:after {
    content: attr(data);
}

JavaScript

// Get DOM objects ready
var checkbox = document.querySelector('input[type="checkbox"]'),
    iframeload = document.querySelector('#download');

// Set up function to change URL
function chooseUrl() {
    var url =
        checkbox.checked ? 'http://knlofficial.com/bite/' : 'http://knlofficial.com';
    
    iframeload.setAttribute('data', url);
}

// Change URL on checkbox value change
checkbox.addEventListener('change', chooseUrl);

// Run chooseUrl once to set initial value
chooseUrl();