Long-lived token security
If you're using a long-lived token, you can append the token to the URLs specified in the mapservice and geometryservice attributes. Alternatively, you can use a proxy page without appending the token value.
For example:
<CONFIG mapservice="http://Server/ArcGIS/services/SampleService/
MapServer?token=Fjv7ubTr0sjmhFQLC8VlbZV1Iq4zn6rfI7rsjhlzvcw."
geometryservice="http://SampleServer/ArcGIS/services/Geometry/
GeometryServer?token=Fjv7ubTr0sjmhFQLC8VlbZV1Iq4zn6rfI7rsjhlzvcw.">
</CONFIG>