如何获取在discord.js v12上创建帐户的日期？

const Discord = require('discord.js');
const client = new Discord.Client();

client.on('ready', () => {
  console.log(`Logged in as ${client.user.tag}`);
});

client.on('message', message => {
  if (message.content === '!accountCreated') {
    const accountCreatedDate = message.author.createdAt;
    message.channel.send(`Your account was created on: ${accountCreatedDate}`);
  }
});

client.login('YOUR_DISCORD_TOKEN');