Apps Alert from Mobile based on a value change in Firebase

[asdafw]

Hi,

I am trying to develop an app which will sound an alarm when value in Firebase db changes.
I am a part-time db admin and I want to get notified when ever a server is down or not accessible so that i can alert other team members. For this, I thought i can develop an app which will get triggered (with an alert sound) when the value in Firebase db changes (value in Firebase db will be updated from scripts running in other servers). I have completed the app but it only rings when the app is in the Foreground.
I am not an expert and i have developed this app by taking snippets from the internet. I am not sure whether this is the correct approach.
Could someone please guide me how WhatsApp notifies messages even though the app is killed? I can concentrated on that part of features and develop the app accordingly.

Many thanks!
-Sam

 

[Deleted User]

Sounds like a job for Firebase Cloud Messaging (FCM)

https://firebase.google.com/docs/cloud-messaging/