JSFiddle - React, Tailwind, and code Playground

HTML

<FORM NAME="myform" ACTION="" METHOD="GET">
Your Options:
<INPUT TYPE="button" NAME="button" VALUE="Click" onClick="runList()"/>
<SELECT NAME="list" ID="list">
<OPTION>test</OPTION>
</SELECT>

JavaScript

function runList(){
    var select = document.getElementById('list');
    select.options[select.options.length] = new Option('Hello', 'Hello');
}