title: How can I make this script run
body: <p>I found this script (tutorial) on GitHub (<a href="https://github.com/amyoshino/Dash_Tutorial_Series/blob/master/ex4.py" rel="nofollow noreferrer">https://github.com/amyoshino/Dash_Tutorial_Series/blob/master/ex4.py</a>) and I am trying to run in my local machine.
  Unfortunately I am having and Error
  <a href="https://i.stack.imgur.com/VQi5w.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VQi5w.png" alt="enter image description here"></a></p>
  
  <p>I would really appreciate if anyone can help me to run this script.
  Perhaps this is something easy but I am new in coding.</p>
  
  <p>Thank you!</p>