JSFiddle - React, Tailwind, and code Playground
HTML
<select id="combo" name="comboname">
<option value="_"></option>
<option value="somevalue">somename</option>
<option value="somevalue1">somename1</option>
</select>
<div id="textbox">
</div>
JavaScript
$("#combo").change(function () {
if (this.value != '_') {
$("#textbox").empty().append("<input type='text' id='text1'/>");
}
else {
$("#textbox").hide();
}
});