JSFiddle - React, Tailwind, and code Playground

HTML

<form name="myform" onsubmit="return (function(el){for(var i=el.length;i--;) if (el[i].checked) return 1})(document.myform.region)||alert('please select item')">
  <label><input type="radio" value="1" name="region">1</label><br>
        <label><input type="radio" value="2" name="region">2</label><br>
  <input type="submit" value="Submit button">
</form>
  <br>
<a href="javascript:void(0)" onclick="(function(el){for(var i=el.length;i--;) if (el[i].checked) return el[i].form.submit()||1})(document.myform.region)||alert('please select item')">Submit link</a><br>