Hi Andreas,

The server admin console for sending messages is only meant for testing that everything works, that is why it only supports ‘simple’ messages. What you want to do is integrate it with your server and send messages via the REST api that UnfiedPush Server has. There are several clients for server side integration 

java https://github.com/aerogear/aerogear-unifiedpush-java-client

node https://github.com/aerogear/aerogear-unifiedpush-nodejs-client

php https://github.com/aerogear/aerogear-unified-push-php-client

Have a look at the message format to see how to send extra information:

For testing this you could use curl, to invoke the restful endpoint.

Hope this helps,

Erik Jan