I am using Firebase database in my app, and I need to send a notification to the Admin when a new order is added to the database "new child added to the database".
I found something called Firebase cloud messaging but I don't know how to use it.
Any help, please?
The Firebase Cloud Messaging is used to send push notification to a devices or a group of devices.The thing that you want to achive can be implemented by using Cloud Functions for more details
HERE
Codelab
You need to specify a node which will be trigger when a child is added to a database in cloud function and than in that cloud function you can write your logic to send push notification to the admin
This Example will help to you start with