databag/app/mobile/index.js

/**
 * @format
 */

import {AppRegistry} from 'react-native';
import App from './App';
import {name as appName} from './app.json';
import messaging from '@react-native-firebase/messaging';

messaging().registerDeviceForRemoteMessages().then(() => {}).catch((err) => {
  console.log(err);
});
messaging().setBackgroundMessageHandler(async remoteMessage => {});

AppRegistry.registerComponent(appName, () => App);