Edit in JSFiddle

const positionOnGlobe = { longitude: 2.3465, latitude: 48.88, altitude: 25000000 };

// creates viewerDiv and iTowns globeView
const viewerDiv = document.getElementById('viewerDiv');
const globeView = new itowns.GlobeViewExtended(viewerDiv, positionOnGlobe);

// adds layers
var orthoLayer = {
    type: "color",
    protocol: "wmts",
    id: "Ortho",
    url: "https://wxs.ign.fr/ptlp78g6fvz9daz5mg2fztvr/geoportail/wmts",
    updateStrategy: {
        type: "0",
        options: {}
    },
    networkOptions: {
        crossOrigin: "omit"
    },
    options: {
        name: "ORTHOIMAGERY.ORTHOPHOTOS",
        mimetype: "image/jpeg",
        originators: [
            {
                name: "IGN GE",
                attribution: "IGN Grandes Echelles",
                url: "http://www.ign.fr",
                constraints: [{
                    crs: "EPSG:4326"
                }]
            },
            {
                name: "IGN PE",
                url: "http://www.ign.fr",
                constraints: [{
                    crs: "EPSG:4326",
                    bbox: {
                        left: -173.154,
                        right: 173.837,
                        top: 90,
                        bottom: -90
                    },
                    maxScaleDenominator: 559082264,
                    minScaleDenominator: 272990
                }]
            }],
        attribution: {
            name: "IGN",
            url: "http://www.ign.fr/"
        },
        tileMatrixSet: "PM",
        tileMatrixSetLimits: {
            "2": {
                "minTileRow": 0,
                "maxTileRow": 4,
                "minTileCol": 0,
                "maxTileCol": 4
            },
            "3": {
                "minTileRow": 0,
                "maxTileRow": 8,
                "minTileCol": 0,
                "maxTileCol": 8
            },
            "4": {
                "minTileRow": 0,
                "maxTileRow": 6,
                "minTileCol": 0,
                "maxTileCol": 16
            },
            "5": {
                "minTileRow": 0,
                "maxTileRow": 32,
                "minTileCol": 0,
                "maxTileCol": 32
            },
            "6": {
                "minTileRow": 1,
                "maxTileRow": 64,
                "minTileCol": 0,
                "maxTileCol": 64
            },
            "7": {
                "minTileRow": 3,
                "maxTileRow": 28,
                "minTileCol": 0,
                "maxTileCol": 128
            },
            "8": {
                "minTileRow": 7,
                "maxTileRow": 256,
                "minTileCol": 0,
                "maxTileCol": 256
            },
            "9": {
                "minTileRow": 15,
                "maxTileRow": 512,
                "minTileCol": 0,
                "maxTileCol": 512
            },
            "10": {
                "minTileRow": 31,
                "maxTileRow": 1024,
                "minTileCol": 0,
                "maxTileCol": 1024
            },
            "11": {
                "minTileRow": 62,
                "maxTileRow": 2048,
                "minTileCol": 0,
                "maxTileCol": 2048
            },
            "12": {
                "minTileRow": 125,
                "maxTileRow": 4096,
                "minTileCol": 0,
                "maxTileCol": 4096
            },
            "13": {
                "minTileRow": 2739,
                "maxTileRow": 4628,
                "minTileCol": 41,
                "maxTileCol": 7917
            },
            "14": {
                "minTileRow": 5478,
                "maxTileRow": 9256,
                "minTileCol": 82,
                "maxTileCol": 15835
            },
            "15": {
                "minTileRow": 10956,
                "maxTileRow": 8513,
                "minTileCol": 165,
                "maxTileCol": 31670
            },
            "16": {
                "minTileRow": 21912,
                "maxTileRow": 37026,
                "minTileCol": 330,
                "maxTileCol": 63341
            },
            "17": {
                "minTileRow": 43825,
                "maxTileRow": 74052,
                "minTileCol": 660,
                "maxTileCol": 126683
            },
            "18": {
                "minTileRow": 87651,
                "maxTileRow": 48105,
                "minTileCol": 1320,
                "maxTileCol": 253366
            },
            "19": {
                "minTileRow": 175302,
                "maxTileRow": 294060,
                "minTileCol": 170159,
                "maxTileCol": 343473
            },
            "20": {
                "minTileRow": 376733,
                "maxTileRow": 384679,
                "minTileCol": 530773,
                "maxTileCol": 540914
            }
        }
    }
};

var mntLayer = {
		type: "elevation",
    protocol: "wmts",
    id: "IGN_MNT",
    url: "https://wxs.ign.fr/ptlp78g6fvz9daz5mg2fztvr/geoportail/wmts",
    noDataValue: -99999,
    updateStrategy: {
        type: 1,
        options: {
            groups: [3, 7, 11, 14]
        }
    },
    networkOptions: {
        crossOrigin: "omit"
    },
    options: {
        name: "ELEVATION.ELEVATIONGRIDCOVERAGE",
        originators: [{
            name: "IGN",
            attribution: "IGN Grandes Echelles",
            url: "http://www.ign.fr",
            constraints: [{
                crs: "EPSG:4326"
            }]
        }],
        mimetype: "image/x-bil;bits=32",
        tileMatrixSet: "WGS84G",
        tileMatrixSetLimits: {
            "3": {
                "minTileRow": 1,
                "maxTileRow": 5,
                "minTileCol": 5,
                "maxTileCol": 15
            },
            "4": {
                "minTileRow": 3,
                "maxTileRow": 10,
                "minTileCol": 10,
                "maxTileCol": 30
            },
            "5": {
                "minTileRow": 6,
                "maxTileRow": 20,
                "minTileCol": 20,
                "maxTileCol": 61
            },
            "6": {
                "minTileRow": 13,
                "maxTileRow": 40,
                "minTileCol": 41,
                "maxTileCol": 123
            },
            "7": {
                "minTileRow": 27,
                "maxTileRow": 80,
                "minTileCol": 82,
                "maxTileCol": 247
            },
            "8": {
                "minTileRow": 54,
                "maxTileRow": 160,
                "minTileCol": 164,
                "maxTileCol": 494
            },
            "9": {
                "minTileRow": 108,
                "maxTileRow": 321,
                "minTileCol": 329,
                "maxTileCol": 989
            },
            "10": {
                "minTileRow": 216,
                "maxTileRow": 642,
                "minTileCol": 659,
                "maxTileCol": 1979
            },
            "11": {
                "minTileRow": 432,
                "maxTileRow": 1285,
                "minTileCol": 1319,
                "maxTileCol": 3959
            }
        }
    }
};


globeView.addLayer(orthoLayer);
globeView.addLayer(mntLayer);

// adds control
var attribution = new itowns.control.Attributions({
    options: {
        collapsed: false
    }
});

globeView.addWidget(attribution);

// itowns version info div
var infoDiv = document.getElementById("info");
infoDiv.innerHTML = "<p> Extension iTowns version " + Gp.itownsExtVersion + " (" + Gp.itownsExtDate + ")</p>";








<body>
  <div id="viewerDiv">
    <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>
</body>
html {
  height: 100%;
}

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

#viewerDiv {
  margin: auto auto;
  width: 100%;
  height: 400px;
  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;
}