Show empty popup when clicking existing boulders

[Humorloos]

See example here https://openlayers.org/en/latest/examples/ relevant code:

// display popup on click
map.on('click', function (evt) {
  const feature = map.forEachFeatureAtPixel(evt.pixel, function (feature) {
    return feature;
  });
  if (feature) {
    popup.setPosition(evt.coordinate);
    $(element).popover({
      placement: 'top',
      html: true,
      content: feature.get('name'),
    });
    $(element).popover('show');
  } else {
    $(element).popover('dispose');
  }
});

// change mouse cursor when over marker
map.on('pointermove', function (e) {
  const pixel = map.getEventPixel(e.originalEvent);
  const hit = map.hasFeatureAtPixel(pixel);
  map.getTarget().style.cursor = hit ? 'pointer' : '';
});
// Close the popup when the map is moved
map.on('movestart', function () {
  $(element).popover('dispose');
});