JSFiddle - React, Tailwind, and code Playground

HTML

<div class="input-group">
  <input type="text" class="form-control" id="elem">
  <select name="" id="">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
  </select>
</div>
<div class="input-group-append">
  <button onclick="addItem()">Добавить</button>
</div>
<ul id="dynamic-list">

</ul>

JavaScript

function addItem(){
	let ul = document.querySelector("#dynamic-list")
  let input = document.querySelector("#elem")
  
  let li = document.createElement("LI")
  li.id = input.value
  li.innerText = input.value
  ul.appendChild(li)
  
  let select = document.querySelector("select")
  let selected = select.children[select.selectedIndex].value;
  
  let input_2 = document.createElement("INPUT")
  input_2.value = "Selected:" + selected
  						 + " Input: " + input.value
  ul.appendChild(input_2);
}