JSFiddle - React, Tailwind, and code Playground

HTML

<form action="" name="formName">
            <input type="radio" name="level" value="8">Beginner<br> 
            <input type="radio" name="level" value="4">Intermediate<br>
            <input type="radio" name="level" value="2">Pro<br>        
          </form>

JavaScript

$("input:radio[name=level]").click(function(){
        var radios = document.formName.level;
            
            for (var i=0, iLen=radios.length; i<iLen; i++) {
              radios[i].disabled = true;
            } 
    });