index.html

## index.html
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
    <title>My First Map</title>
    <style>
      html,
      body,
      #viewDiv {
        padding: 0;
        margin: 0;
        height: 100%;
        width: 100%;
      }
    </style>
    <link
      rel="stylesheet"
      href="https://js.arcgis.com/4.12/esri/themes/light/main.css"
    />
    <script src="https://js.arcgis.com/4.12/"></script>
    <script>
      require(["esri/WebMap", "esri/views/MapView"], function(WebMap, MapView) {
        // create a map instance
        const webmap = new WebMap({
          portalItem: {
            id: "be4b2af07b5a4d40a4deeae1b11fe3cc"
          }
        });
        // create a view to display
        // our map data
        const view = new MapView({
          container: "viewDiv",
          map: webmap
        });
      });
    </script>
  </head>
  <body>
    <div id="viewDiv"></div>
  </body>
</html>