JSFiddle - React, Tailwind, and code Playground

HTML

<select name="level" onChange="changeTest(this)">
       <option value="1" selected="selected">Administrator</option>
                 <option value="2">Manager</option>
                 <option value="3">HR Staff</option>
     </select>

JavaScript

function changeTest(obj){
        alert(obj.options[obj.selectedIndex].value);
      }