JSFiddle - React, Tailwind, and code Playground

HTML

<select id="list">
  <option value="v">Volvo</option>
  <option value="s">Saab</option>
  <option value="o">Opel</option>
  <option value="a">Audi</option>
</select>

JavaScript

document.getElementById("list").options[1].selected = true;
  // this sets "saab" option as true.
  // or...
  //document.getElementById("list").value = "s"; // ID, not innerHTML.