JSFiddle - React, Tailwind, and code Playground

HTML

<input id="searchbar" oninput=filterList();>
<ul id="myList">
<li><a>Lorem</a></li>
<li><a>Ipsum</a></li>
<li><a>Dolor</a></li>
<li><a>sit</a></li>
<li><a>amet</a></li>
<li><a>consectetur</a></li>
<li><a>adipisicing</a></li>
<li><a>Loram</a></li>
<li><a>elit</a></li>
<li><a>Ippsum</a></li>
<li><a>Perspiciatis</a></li>
<li><a>vitae</a></li>
<li><a>Possimus</a></li>
<li><a>recusandae</a></li>
<li><a>omnis</a></li>
<li><a>beatae</a></li>
</ul>

JavaScript

function filterList() {
	const listElements = [...document.getElementById("myList").children].map(x => x.firstChild);
  const searchterm = document.getElementById("searchbar").value;
  console.log(searchterm);
  for(const el of listElements) {
  	if(!el.textContent.toLowerCase().startsWith(searchterm.toLowerCase())) el.parentElement.style.display = "none";
    else el.parentElement.style.display = "";
  }
}