Edit in JSFiddle

function go() {

  map = L.map("map").setView([45, 6], 13);

  var lyrOrtho = L.geoportalLayer.WMTS({
    layer: "ORTHOIMAGERY.ORTHOPHOTOS",
  });
  map.addLayer(lyrOrtho);
  var ep = L.geoportalControl.ElevationPath({
  });
  map.addControl(ep);

}

Gp.Services.getConfig({
  apiKey: "essentiels",
  onSuccess: go
});

var infoDiv = document.getElementById("info");
infoDiv.innerHTML = "<p> Extension Leaflet version " + Gp.leafletExtVersion + " (" + Gp.leafletExtDate + ") - Leaflet version : " + L.version + " </p>";

<div id="map"></div>
<div id="info"></div>

#map {
  padding: 5px;
  width: 100%;
  height: 300px;
  box-shadow: 0 0 10px #999;
}

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