I've implemented a header with a navbar inside.
I want to create a dropdown menu element, but for some reason, my item is not appearing.
On this link, it looks simple: https://getbootstrap.com/docs/4.0/components/navs/
Pills with dropdowns
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
<header>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button" aria-haspopup="true" aria-expanded="false">Dropdown</a>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Separated link</a>
</div>
</li>
<header>ITEC-EP
<div class="collapse navbar-collapse" id="navbarColor01">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="index.html">Applications<span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="wiki.html">Wiki</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button" aria-haspopup="true" aria-expanded="false">Dropdown</a>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Separated link</a>
</div>
</li>
</ul>
</div>
No error message is displayed. When clicking on the dropdown menu, nothing happens. The inner elements are not showing up.
I'm attempting to use only bootstrap without CSS. I've opted for this template:
What am I doing wrong? How can I debug in developer mode in Mozilla in the future?