openlayers-8.x-4.x-dev/src/Plugin/Source/TileUTFGrid/js/TileUTFGrid.js

Drupal.openlayers.pluginManager.register({
  fs: 'openlayers.Source:TileUTFGrid',
  init: function(data) {
    return new ol.source.TileUTFGrid(data.opt);
  }
});