Displaying the name of an indoor map

Show the name of an indoor map in a Leaflet popup. Click one of the blue markers to enter an indoor map. Close the popup bubble to exit the building.

<!DOCTYPE HTML>
<html>
  <head>
    <script src="https://unpkg.com/wrld.js@1.x.x"></script>
    <link href="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.0.1/leaflet.css" rel="stylesheet" />
  </head>
  
  <body>
  <div style="position: relative">
    <div id="map" style="height: 400px"></div>
    <script>
      var map = Wrld.map("map", "your_api_key_here", {
        center: [37.782014, -122.404748],
        zoom: 17,
        indoorsEnabled: true
      });
      
      function onIndoorMapEntered(event) {        
        var latLng = map.getCenter();        
        var indoorMapId = event.indoorMap.getIndoorMapId();
        var buildingName = event.indoorMap.getIndoorMapName();
        
        var popupOptions = { 
          indoorMapId: indoorMapId, 
          indoorMapFloorIndex: 0, 
          autoClose: false, 
          closeOnClick: false 
        };
        
        var popup = Wrld.popup(popupOptions)
          .setLatLng(latLng)
          .addTo(map)
          .setContent(buildingName);
        
        map.on("popupclose", function() { map.indoors.exit(); });
      }

      map.indoors.on("indoormapenter", onIndoorMapEntered);
    </script>
  </div>
  </body>
</html>