我有这个错误：map.js:33 Uncaught TypeError: event.target.getPosition is not a function at yn.<anonymous> (map.js:33)

如何解决我有这个错误：map.js:33 Uncaught TypeError: event.target.getPosition is not a function at yn.<anonymous> (map.js:33)

它没有向我显示 infobubble 弹出窗口，我尝试更改代码，在第 33 行，但它仍然不起作用。

    var ui = H.ui.UI.createDefault(map,defaultLayers);
    var marker1 = new H.map.Marker({ lat: 47.045299,lng: 21.919435 });
     marker1.setData
(
   "<p> Universitatea din Oradea,Facultatea de Geografie,Turism și Sport <br> Adresa: <br> Nume Masterat:<br> Număr de 
        Studenți: 
  </p > "
);
      marker1.addEventListener("tap",event => {
         var bubble = new H.ui.InfoBubble(
             ***event.target.getPosition(),***
              {
                 content: event.target.getData()
              }
          );
       ui.addBubble(bubble);
    },false);