Here is the code I have to load the layer up:
But nothing loads up. When I look in Chrome's developer tools and goto "Network" you can see it connects to the layer:
I initially tried this on a layer that was projected to British National Grid, but this layer is based projected to Web Mercator and have ensured that the standard ArcGIS Online caching type is used.
If anyone has any suggestions I would be grateful. At first I thought it was a "tokens" problem but a FeatureLayer seems to load up fine.