title: (node:15976) UnhandledPromiseRejectionWarning when trying to connect to mongodb
body: <p>The code to connect to mongodb and why do I get an error on async.</p>
  <p><a href="https://i.stack.imgur.com/Ce4he.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ce4he.jpg" alt="enter image description here" /></a></p>
  <p>And when I execute <code>npm run start</code> I get the following error</p>
  <p><a href="https://i.stack.imgur.com/KVflE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KVflE.png" alt="enter image description here" /></a></p>
  <p>Please help ! Thank you.</p>