我试图了解在调用任务时如何发送通知，但我遇到了错误，我不明白为什么以及如何修复此问题。
这就是错误：
taskmanager:任务“后台提取”失败：，[typeerror:undefined不是一个函数（靠近“…notifications.presentlocalnotificationasync…”）
代码如下：

import React, { useEffect, useState } from 'react';
import { StyleSheet, Text, View, Button, StatusBar } from 'react-native';
import * as BackgroundFetch from 'expo-background-fetch';
import * as TaskManager from 'expo-task-manager';
import * as Notifications from 'expo-notifications';
const BACKGROUND_FETCH_TASK = 'background-fetch';

// 1. Define the task by providing a name and the function that should be executed
// Note: This needs to be called in the global scope (e.g outside of your React components)
TaskManager.defineTask(BACKGROUND_FETCH_TASK, async () => {
  const now = Date.now();
  console.log(`Got background fetch call at date: ${new Date(now).toISOString()}`);

  await Notifications.presentLocalNotificationAsync({
    title: 'This is crazy',
    body: 'Your mind will blow after reading this',
  });

  // Be sure to return the successful result type!
  return BackgroundFetch.Result.NewData;
});

// 2. Register the task at some point in your app by providing the same name, and some configuration options for how the background fetch should behave
// Note: This does NOT need to be in the global scope and CAN be used in your React components!
async function registerBackgroundFetchAsync() {
  return BackgroundFetch.registerTaskAsync(BACKGROUND_FETCH_TASK, {
    minimumInterval: 1, // 15 minutes
    stopOnTerminate: false, // android only,
    startOnBoot: true, // android only
    delay: 1000,
    periodic: true,
  });
}

// 3. (Optional) Unregister tasks by specifying the task name
// This will cancel any future background fetch calls that match the given name
// Note: This does NOT need to be in the global scope and CAN be used in your React components!
async function unregisterBackgroundFetchAsync() {
  return BackgroundFetch.unregisterTaskAsync(BACKGROUND_FETCH_TASK);
}

const BackgroundFetchScreen = () => {
  const [isRegistered, setIsRegistered] = useState(false);
  const [status, setStatus] = useState(null);

  useEffect(() => {
    checkStatusAsync();
  }, []);

  const checkStatusAsync = async () => {
    const status = await BackgroundFetch.getStatusAsync();
    const isRegistered = await TaskManager.isTaskRegisteredAsync(BACKGROUND_FETCH_TASK);
    setStatus(status);
    setIsRegistered(isRegistered);
  };

  const toggleFetchTask = async () => {
    if (isRegistered) {
      await unregisterBackgroundFetchAsync();
    } else {
      await registerBackgroundFetchAsync();
    }
    checkStatusAsync();
  };

  return (
    <>
      <View style={styles.textContainer}>
        <Text>
          Background fetch status:{' '}
          <Text >{status ? BackgroundFetch.Status[status] : null}</Text>
        </Text>
        <Text>
          Background fetch task name:{' '}
          <Text >
            {isRegistered ? BACKGROUND_FETCH_TASK : 'Not registered yet!'}
          </Text>
        </Text>
      </View>
      <View style={styles.textContainer}></View>
      <Button
        title={isRegistered ? 'Unregister BackgroundFetch task' : 'Register BackgroundFetch task'}
        onPress={toggleFetchTask}
      />
    </>
  );
}

const styles = StyleSheet.create({
  textContainer: {
    flex: 1,
    marginTop: StatusBar.currentHeight || 0,
  },

});

export default BackgroundFetchScreen;

我将感谢任何帮助和信息，我可以得到。