Use version 4 TileJSON from mapbox

examples/popup.html

@@ -7,6 +7,9 @@ docs: >
     Click on the map to get a popup.  The popup is composed of a few basic elements: a container, a close button, and a place for the content.  To anchor the popup to the map, an <code>ol/Overlay</code> is created with the popup container.  A listener is registered for the map's <code>click</code> event to display the popup, and another listener is set as the <code>click</code> handler for the close button to hide the popup.
   </p>
 tags: "overlay, popup"
+cloak:
+  - key: pk.eyJ1IjoidHNjaGF1YiIsImEiOiJjaW5zYW5lNHkxMTNmdWttM3JyOHZtMmNtIn0.CDIBD8H-G2Gf-cPkIuWtRg
+    value: Your Mapbox access token from https://mapbox.com/ here
 ---
 <div id="map" class="map"></div>
 <div id="popup" class="ol-popup">