I haven'te tested this app with Portal, yet, but I beileve you will need to update the proxy.config to supply the clientId and app secret. Ex:
<serverUrl url="http://route.arcgis.com/arcgis/rest/" matchAll="true"
clientId="APP ID"
clientSecret="APP SECRET"
rateLimit="50"
rateLimitPeriod="10"
></serverUrl>