JSFiddle - React, Tailwind, and code Playground

HTML

<form>
  <select name="genre" multiple>
    <option value="blues" >Мягкий блюз</option>
    <option value="rock" >Жёсткий рок</option>
    <option value="classic">Классика</option>
  </select>
</form>

JavaScript

var form = document.forms[0];

var select = form.elements.genre;

var option = new Option("Electro House", "electroHouse");

select.appendChild(option).selectedIndex = 0;