Why does ShowDirectoryPicker hang?

I try to add folder scanning into my web page. Folder selection works fine and I get prompted if I want to allow the access to selected folder. But then nothing happens. In console I see "1" as the last log entry, so await never returns.

Any ideas what I should do?

jQuery(document).ready(function ($) {
  const butDir = document.getElementById('butDirectory');
  butDir.addEventListener('click', async() => {
    console.log("1");
    const dirHandle = await window.showDirectoryPicker();
    console.log("2");
    const promises = [];
    for await (const entry of dirHandle.values()) {
      if (entry.kind !== 'file') {
        continue;
      }
      promises.push(entry.getFile().then((file) => `${file.name} (${file.size})`));
    }
    console.log(await Promise.all(promises));
  });
});

OK, got it working. Instead of having the code inside jquery.ready() I had to move it outside:

async function getDir() {
  const dirHandle = await window.showDirectoryPicker();
}

and call it directly from HTML

<input type="button" ... onclick="javascript:getDir();"/>