How to show React Native Push Notification when app is closed

Firebase cloud messaging is available even if your app is closed. However, if someone changes data, it is not possible because the program terminates all activity when it is closed. To call your task in the background, you must utilize Headless JavaScript. However, you should try react-native-background-fetch for app optimization. Then set your job to run in the background.

Here's how to go about it:

step 1: install the react-native npm background package

step 2: develop a headless js

step 3: insert your task inside it ( as shown below)

...
const ref = firestore().collection('players');
return ref.onSnapshot(querySnapshot => {
querySnapshot.forEach(doc => {
....
// called push notification
PushNotification.localNotification({
channelId,
title,
message,
bigText,
});
});
});
...