JSFiddle - React, Tailwind, and code Playground

HTML

<button id="button" onlick="duplicate()">Add another plan</button>
<div id="duplicater">
    <p>Choose Your Mobile Plan</p>
    <select>
        <option value="1">Package 1</option>
        <option value="2">Package 2</option>
        <option value="3">Package 3</option>
        <option value="4">Package 4</option>
        <option value="5">Package 5</option>
        <option value="6">Package 6</option>
    </select>
</div>

JavaScript

document.getElementById('button').onclick = duplicate;

var original = document.getElementById('duplicater');

var i = 1;

function duplicate() {
    if (i < 6) {
        var clone = original.cloneNode(true); // "deep" clone
        clone.id = "duplicater" + i++; // there can only be one element with an ID
        original.parentNode.appendChild(clone);
    }
}