Error When Doing Initial Setup

Hi Gregorz - I'm doing this within VS Code for a Django web application. But having trouble even following the simple quick install instructions.

For example, if I go to my downloads page:
--> download "MDB5-STANDARD-UI-KIT-PRO-ESSENTIAL-3.9.0"
--> unzip the package
--> open the folder
--> open the index.html file in Chrome -- everything seems to be functioning
--> if I replace it with Lightbox component, that seems to work too
--> However, if I replace the code in index.html between the start and end project comments with:

    <div class="multi-ranges-basic"></div>
<div id="multi-ranges-basic-value" class="mt-3">
  Value:
  <span class="d-flex flex-column">
    <div>First:</div>
    <div>Second:</div>
  </span>
</div>

I only see the text of Value:, First:, Second:. I don't see a slider.

I then added:

    <link rel="stylesheet" href="css/modules/multi-range.min.css" />

under:

<link rel="stylesheet" href="css/mdb.min.css" />

And then I added:

<script type="text/javascript" src="js/modules/multi-range.min.js"></script>

under:

<script type="text/javascript" src="js/mdb.min.js"></script>

But that didn't make a difference. What am I doing wrong?