html

<input type="file" id="filepicker" multiple />
<div>
  <p>List of selected files:</p>
  <ul id="output"></ul>
</div>

js

const output = document.getElementById("output");
const filepicker = document.getElementById("filepicker");

filepicker.addEventListener("change", (event) => {
  const files = event.target.files;
  output.textContent = "";

  for (const file of files) {
    const li = document.createElement("li");
    li.textContent = file.name;
    output.appendChild(li);
  }
});