JSFiddle - React, Tailwind, and code Playground

HTML

<form>
        <select id="categories"

name="users" onchange="showUser(this.value)">
    <option value="">Select a category:</option>
    <option value="movie">Movie</option>
    <option value="musik">Musik</option>
    <option value="books">Books</option>
    <option value="images">Images</option>
    </select>
    </form>

JavaScript

var categories = document.getElementById("categories");

var newOption = document.createElement('option');
newOption.innerText = "New value";
newOption.setAttribute('value', 'newvalue');

categories.appendChild(newOption);