Firebase is used for storing your offline data. It syncs across your devices when logging in with the same account. Firebase is also used for pushing notification later versions. After finishing this step, you can mostly complete the getting start of the guide.
You need to get the fire base ID and replay from the App/Common/Config.js
The id could be get from the Firebase Dashboard or the database page:
Example: beonews-ef22f.firebaseio.com
And make sure enable the options for authentication from Firebase: