Приложение React Native Jobs => Push-уведомления: получение ошибки Необработанное отклонение обещания (id: 0): ошибка: запрос не выполнен со статусом 500

Question

Я получаю сообщения об ошибках ниже на своем мобильном телефоне и терминале expo и, следовательно, не могу сгенерировать expo-токен для службы push-уведомлений:

Expo-токен необходим бэкэнд-серверу для отправки текстового сообщения.И я сталкиваюсь с ошибкой, генерирующей это.

Журнал экспозиционного терминала

Журнал устройства Android

push_notifications_service.js:

import { Permissions, Notifications } from 'expo';
import { AsyncStorage } from 'react-native';
import axios from 'axios';

const PUSH_ENDPOINT = "http://rallycoding.herokuapp.com/api/tokens"

export default async () => {
  let previousToken = await AsyncStorage.getItem('pushtoken');
  console.log(previousToken);
  if (previousToken) {
    return;
  } else {
    let { status } = await Permissions.askAsync(Permissions.NOTIFICATIONS);

    if (status !== 'granted') {
      return;
    }

    let token = await Notifications.getExpoPushTokenAsync();
    await axios.post(PUSH_ENDPOINT, { token: { token } });
    AsyncStorage.setItem('pushtoken', token);
  }
};

App.js:

import React from 'react';
import { StyleSheet, View, Alert } from 'react-native';
import { createStore, applyMiddleware } from 'redux';
import { Provider } from 'react-redux';
import ReduxThunk from 'redux-thunk';
import { createBottomTabNavigator } from 'react-navigation';
import reducers from './reducers';
import { Notifications } from 'expo';

import LoginScreen from './Modules/Authentication/LoginScreen';
import SignUpScreen_1 from './Modules/Authentication/SignUpScreen_1';
import SignUpScreen_2 from './Modules/Authentication/SignUpScreen_2';
import ConfirmationScreen from './Modules/Authentication/ConfirmationScreen'
import ForgotPasswordScreen from './Modules/Authentication/ForgotPasswordScreen';
import LibraryNotificationScreen from './Modules/Library/LibraryNotificationScreen';
import BarCodeScannerScreen from './Modules/Library/BarCodeScanner'
import FreshArrivalsList from './Modules/Library/FreshArrivalsList';
import AllBooksListScreen from './Modules/Library/AllBooksListScreen';

import registerForPushNotificationsAsync from './Modules/Services/push_notifications_service.js'

export default class App extends React.Component {

  componentDidMount() {
    registerForPushNotificationsAsync();

    // Handle notifications that are received or selected while the app
    // is open. If the app was closed and then opened by tapping the
    // notification (rather than just tapping the app icon to open it),
    // this function will fire on the next tick after the app starts
    // with the notification data.
    this._notificationSubscription = Notifications.addListener(this._handleNotification);
  }

  _handleNotification = (notification) => {
    this.props.navigation.navigate('libraryNotifications');
  };


  render() {
    const MainNavigator = createBottomTabNavigator({

        library: {
          screen: createBottomTabNavigator({
            all_books_list: { screen: AllBooksListScreen },
            freshArrivals: { screen: FreshArrivalsList },
           })
         },
       barCodeScanner: { screen: BarCodeScannerScreen },
       libraryNotifications: { screen: LibraryNotificationScreen},

        login: { screen: LoginScreen },
        forgot_password: { screen: ForgotPasswordScreen },

        sign_up: { 
          screen: createBottomTabNavigator({
            sign_up_1: { screen: SignUpScreen_1 },
            sign_up_2: { screen: SignUpScreen_2 },
            otp_confirmation: { screen: ConfirmationScreen }
          }, {
            navigationOptions: {
              tabBarVisible: false
            }
          })
        }
      }, {
        navigationOptions: {
          tabBarVisible: false
        }, lazy: true
    });

    const store = createStore(reducers, {}, applyMiddleware(ReduxThunk));

    return (
      <Provider store={store}>
        <View style={styles.container}>
          <MainNavigator />
      </View>
      </Provider>
    );
  }
}

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