Unified Android SDK Push Notifications

Unified SDK

• I am struggling with push notifications. We are not able to get push notification for agent's messages when the app is in background or closed. I have followed the following documentation but not able to receive push notifications. It makes sense as there as generally any 3rd party server (i.e. zendesk) would require FCM server key to register the push tokens from client side (android).

• As explained in article: Enabling push notifications for the Chat SDK V2 for multiple mobile apps
  We have no option if mobile sdk Chat Dashboard-> Settings > Account > API & SDKs. (Screenshot Below)
  to add FCM server key. Can you please tell why do we have different behaviour? Is is related to our subscription plan or something else?