setApplicationIconBadgeNumber in react native not showing number on app icon

I am having trouble displaying the number of unread messages outside the app icon.

I proceeded to install the library @react-native-community/push-notification-ios and used PushNotificationIOS.setApplicationIconBadgeNumber(10) to display the number of unread messages on the application icon. when I exit the app, I don't see the number of unread messages appearing on the icon.

Please help me.