App.js

import { StatusBar } from 'expo-status-bar';
import React, {useEffect} from 'react';
import { Platform, StyleSheet, Text, View } from 'react-native';
import AsyncStorage from '@react-native-community/async-storage';
import keys from './constants/Keys';
import Parse from "parse/react-native.js";

Parse.setAsyncStorage(AsyncStorage);
Parse.initialize(keys.applicationId, keys.javascriptKey);
Parse.serverURL = keys.serverURL;

export default function App() {

  useEffect(() => {
    const createInstallation = async () => {
      const Installation = Parse.Object.extend(Parse.Installation);
      const installation = new Installation();
  
      installation.set("deviceType", Platform.OS);
  
      await installation.save();
    }

    createInstallation();
  }, []);

  return (
    <View style={styles.container}>
      <Text>Open up App.js to start working on your app!</Text>
      <StatusBar style="auto" />
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
});