I was wrong. I realized that the IdentityManager was in fact appending the token properly. In case others see this post, it seems as though the first request fails with an error code 499 (Token Required). This triggers another request which does have the token appended to it.My issue was complicated by a message that wasn't very clear. I happened to be using the wrong URL, which ended up returning an error code 500 (9004$LAYER_NOT_EXIST) on the second request that did have the token. That error isn't very helpful. For reference, the URL that seemed to work for me is below:http://route.arcgis.com/arcgis/rest/services/World/Route/NAServer/Route_World