Issues on Running the Plugin With ArcGIS JavaScript API 3.21

[BeClevest]

Using the plugin with ArcGIS JavaScript API 3.21 and following documentation from Usage , I am getting following warning and errors:

<script src="https://js.arcgis.com/3.21/"></script>
<script src="geojsonlayer.js"></script>
<script src="terraformer.min.js"></script>
<script src="terraformer-arcgis-parser.js"></script>
<script>
    var map;
    require(["esri/map",
               "geojsonlayer.js",
               "dojo/on",
               "dojo/domReady!"
    ], function(Map, GeoJsonLayer, on) {
        map = new Map("map", {
            center: [-118, 34.5],
            zoom: 2,
            basemap: "topo"
        });

        var geoJsonLayer = new GeoJsonLayer({
            url: "./data/canada.json"
        });

        map.addLayer(geoJsonLayer);
    });
</script>`

Can you please let me know what I am missing?

[Deprecation] Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.

and

Error: multipleDefine

src: dojoLoader