JSFiddle - React, Tailwind, and code Playground
HTML
<select id = "my-id">
<option value="1"></option>
<option value="2"></option>
</select>
JavaScript
document.getElementById("my-id").options[0].value="TEST";
<select id = "my-id">
<option value="1"></option>
<option value="2"></option>
</select>
document.getElementById("my-id").options[0].value="TEST";