openlayers-8.x-4.x-dev/src/Plugin/Control/MousePosition/js/mouseposition.js

Drupal.openlayersPluginManager.register({
  fs: 'openlayers.Control:MousePosition',
  init: function(data) {
    data.opt = data.opt || {};
    data.opt.coordinateFormat = ol.coordinate.createStringXY(4);
    //options.projection = 'EPSG:4326';
    return new ol.control.MousePosition(data.opt);
  }
});