JSFiddle - React, Tailwind, and code Playground

HTML

<input type="radio" name="sitechoice" value="www.websiteone.com">www.websiteone.com
<br />
<input type="radio" name="sitechoice" value="www.secondwebs.com">www.secondwebs.com
<p id="thing2"></p>
<textarea id="textarea"><p id="thing"></p></textarea>

CSS

select {
    width: 300px;
}
textarea {
    width: 300px;
    height: 200px
}

JavaScript

$(document).ready(function () {
    $("input").change(function () {
        // Your normal code
        var website = $(this).val();
        $("#thing2").html(website);
        
        // This turns the textarea's val into a jQuery object ...
        // And inserts it into an empty div that is created
        var textareaHtml = $('<div>' + $("#textarea").val() + '</div>');
        // Here you can do your normal selectors
        textareaHtml.find("#thing").html(website);
        // And this sets the textarea's content to the empty div's content
        $("#textarea").val(textareaHtml.html());
    });
});