In order to integrate Gameball with Segment, you need to do the following:
Add the events you want to track in Gameball dashboard. For more info on how to do that click here.
Add Gameball app as a destination form Segment catalog
Add your Gameball API Key in destinations settings on Segment
You can check if the events you track are reaching Gameball through the Event Tester on Segment with the Event Builder
Also you can test that the events you track reach Gameball through the Event Tester in Segment with the JSON Builder