title: discord.js MessageEmbed fields.flat is not a function
body: <p>I am making a Discord bot using JavaScript and discord.js. There, I want to send a RichEmbed/MessageEmbed (I don't know how it's called) to a channel. Instead of sending an Embed though, it threw an error inside discord.js.</p>
  
  <pre><code>TypeError: fields.flat is not a function
      at Function.normalizeFields (D:\discord-bot\node_modules\discord.js\src\structures\MessageEmbed.js:436:8)
      at MessageEmbed.addFields (D:\discord-bot\node_modules\discord.js\src\structures\MessageEmbed.js:252:42)
      at commands.forEach.command (D:\discord-bot\src\js\core\commands\commandManager.js:55:19)
      at Array.forEach (&lt;anonymous&gt;)
      at helloWorldEmbed (D:\discord-bot\src\js\core\commands\commandManager.js:54:18)
      at Object.call (D:\discord-bot\src\js\core\commands\commandManager.js:29:13)
      at Client.client.on (D:\discord-bot\src\js\core\bot.js:16:49)
      at Client.emit (events.js:182:13)
      at MessageCreateAction.handle (D:\discord-bot\node_modules\discord.js\src\client\actions\MessageCreate.js:31:14)
      at Object.module.exports [as MESSAGE_CREATE] (D:\discord-bot\node_modules\discord.js\src\client\websocket\handlers\MESSAGE_CREATE.js:4:32)
  </code></pre>
  
  <p>I searched already for an answer, but it seems like I'm the only person having trouble with it.</p>
  
  <p>Here's the code I used:</p>
  
  <pre><code>const embed = new MessageEmbed()
      .setTitle('Hello World')
      .setDescription('This is a test.')
      .setColor('#3498db')
  quotes.forEach(quote =&gt; {
      embed.addField(quote.name, quote.description, true)
  })
  message.channel.send('Hello world.', embed)
  </code></pre>