Edit in JSFiddle

Gp.Map.load(
    "map", // html div
    {
        // Geoportal access key obtained here : http://professionnels.ign.fr/ign/contrats
        apiKey: "essentiels,altimetrie,cartes",
        //load the map with itowns (in 3D)
         viewMode : "3d",
        //path to the iTowns library
         enginePath3d: "https://ignf.github.io/geoportal-sdk/latest/dist/3d/",
        // layers to display
        zoom: 6,
        center: {
            x: 2.642212,
            y: 46.811339
        },
        layersOptions: {
            "ORTHOIMAGERY.ORTHOPHOTOS": {},
            "GEOGRAPHICALGRIDSYSTEMS.PLANIGNV2": {
                opacity: 0.3
            },
            "ELEVATION.ELEVATIONGRIDCOVERAGE" : {
            		type : "elevation"
            }
        },
        // additional tools to display on the map
        controlsOptions: {
            "layerSwitcher": {}
        }
    }
);

var infoDiv = document.getElementById("info");
infoDiv.innerHTML = "<p> SDK version " + Gp.sdkVersion + " (" + Gp.sdkDate + ")</p>";

html {
    height: 100%;
}

body {
    margin: 0;
    overflow:hidden;
    height:100%;
}

#map {
    margin : auto auto;
    width: 100%;
    height: 300px;
    padding: 0;
}

#tiltButton {
    background-color: white;
    position: absolute;
    top: 20px;
    left : 50px;
}

#info {
    padding: 5px;
    width: 100%;
    height: 20px;
    font-family: "monospace";
    font-size: 10px;
}

<div id="map">
      <button id="tiltButton">
      jsFiddle bug - click on this text to activate tilt (ctrl + left click)
      <br>
      Do not integrate this button to your own non-jsFiddle pages
    </button>
</div>
<div id="info"></div>