title: Discord.js v12.0.1 channel is undefined
body: <p>I'm trying to get a bot to read the name of a channel from an id. However I should be using the correct code for this.</p>
  
  <p>This is my code:</p>
  
  <pre><code>client.channels.fetch('670722326664314911')
  .then(channel =&gt; console.log(channel.name))
  .catch(console.error);
  </code></pre>
  
  <p>Error: TypeError: Cannot read property 'name' of null</p>