在这行代码中，我试图将私人消息发送给初始消息作者。由于未知原因，出现错误：
（节点：17560）未处理的PromisejectionWarning:typeerror:无法读取未定义的属性“send”
这是一行代码：

const appStart = await message.author.send(questions[collectCounter++]);

以下是整个文件：

const Discord = require("discord.js");
const {Client, Message, MessageEmbed} = require("discord.js");
module.exports = {
    name: 'apply',
    /**
     * 
     * @param {Client} client 
     * @param {Messafe} message 
     * @param {String[]} args 
     */
    run : async(client, message, args) => {
        const questions = [
            "What is your in-game name?",
            "Do you accept the rules?",
            "How old are you?",
            "Where are you from?",
            "How long have you been playing Minecraft?",
            "Where did you find the server?",
            "Have you ever been banned from another server on Minecraft? If yes, what was the reason?",
            "Why should we accept you?",
        ]
        let collectCounter = 0;
        let endCounter = 0;

        const filter = (m) => m.author.id === message.author.id;

        const appStart = await message.author.send(questions[collectCounter++]);        
        const channel = appStart.channel;

        const collector = channel.createMessageCollector(filter);

        collector.on("collect", () => {
            if(collectCounter < questions.length) {
                channel.send(questions[collectedCounter++]);
            } else {
                channel.send("Your application has been sent!");
                collector.stop("fulfilled");
            }
        });

        const appsChannel = client.channel.cache.get('863534867668009004');
        collector.on('end', (collected, reason) => {
            if(reason === 'fulfilled') {
                let index = 1;
                const mappedResponses = collected.map((msg) => {
                    return `&{index++}) &{questions[endCounter++]}\n-> ${msg.content}`
                })
                .join('\n\n');
            }

            appsChannel.send(message.channel.send('New Application!', mappedResponses));
        });
    },
};

这是我的index.js：

const fs = require("fs");
const Discord = require("discord.js");

const client = new Discord.Client();
client.commands = new Discord.Collection();
const commandFiles = fs.readdirSync('./commands').filter(file => file.endsWith('.js'));

const BOT_ID = "863550035923697674";

const prefix = "!";

client.on("ready", () => {
  console.log(`Logged in as ${client.user.tag}!`);
  client.user.setActivity("ur cheat files...", {
    type: "WATCHING",
    url: "https://discord.gg/bzYXx8t3fE"
  });
});

for(const file of commandFiles) {
  const command = require(`./commands/${file}`);
  client.commands.set(command.name, command);
}

client.on("message", message => {
  let userID = message.author.id;
  if (userID == BOT_ID) {
    return;
  }
  const version = "Wersja bota 0.2";
  ///const args = message.content;
  const args = message.content.slice(prefix.length).trim().split(/ +/g);
  const command = args.shift().toLowerCase();
  if(!client.commands.has(command)) return;
  try{
      client.commands.get(command).run(message, args);
  }catch(error){
      console.error(error);
      message.reply('**There was an issue executing that command!**');
  }
});

client.login("tokenishere");

谢谢你的帮助！