Шаблон под дле 9,6

<div id="main-3d-viewer"></div>
<div id="model-buttons"></div>

<!-- Тут выводится ваше доп.поле с файлами -->
<div id="model-links-src" style="display:none;">
  {xfvalue_model_files}
</div>

<script>
document.addEventListener('DOMContentLoaded', function () {
  const src = document.getElementById('model-links-src');
  const box = document.getElementById('model-buttons');
  const links = src ? src.querySelectorAll('a[href]') : [];

  if (!links.length) return;

  // const stl_viewer = new StlViewer(...);

  function fileNameFromUrl(url) {
    try {
      const clean = url.split('?')[0].split('#')[0];
      return decodeURIComponent(clean.substring(clean.lastIndexOf('/') + 1));
    } catch(e) {
      return url;
    }
  }

  function loadModel(url) {
    // stl_viewer.remove_model(0);
    // stl_viewer.add_model({ id:0, filename:url });
    console.log('load:', url);
  }

  links.forEach(function (a, i) {
    const url = a.getAttribute('href');
    const text = (a.textContent || '').trim();
    const title = text && text !== url ? text : fileNameFromUrl(url);

    const btn = document.createElement('button');
    btn.type = 'button';
    btn.className = 'model-btn';
    btn.textContent = title;
    btn.dataset.file = url;
    btn.addEventListener('click', function () { loadModel(url); });

    box.appendChild(btn);
    if (i === 0) loadModel(url);
  });
});
</script>