Given the full-fat Navbar from BootStrap v5.3 Do not include the bootstrap.bundle which might be causing them to conflict.
Modified code should be like this for the dropdown
to work:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>About</title>
<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet"
integrity="sha384-GLhlTQ8iRABdZLl6O3oVMWSktQOp6b7In1Zl3/Jr59b6EGGoI1aFkw7cmDA6j6gD" crossorigin="anonymous">
</head>
<body >
<nav >
<div >
<a href="#">Navbar</a>
<button type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span ></span>
</button>
<div id="navbarSupportedContent">
<ul >
<li >
<a aria-current="page" href="#">Home</a>
</li>
<li >
<a href="#">Link</a>
</li>
<li >
<a href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul >
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><hr ></li>
<li><a href="#">Something else here</a></li>
</ul>
</li>
<li >
<a >Disabled</a>
</li>
</ul>
<form role="search">
<input type="search" placeholder="Search" aria-label="Search">
<button type="submit">Search</button>
</form>
</div>
</div>
</nav>
<h1>Hello, world!</h1>
<!-- <script type="text/javascript"
src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js""
integrity="sha384-w76AqPfDkMBDXo30jS1Sgez6pr3x5MlQ1ZAGC nuZB EYdgRZgiwxhTBTkF7CXvN" crossorigin="anonymous">
</script> -->
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/@popperjs/[email protected]/dist/umd/popper.min.js"
integrity="sha384-oBqDVmMz9ATKxIep9tiCxS/Z9fNfEXiDAYTujMAeBAsjFuCZSmKbSSUnQlmh/jp3" crossorigin="anonymous">
</script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js" integrity="sha384-mQ93GR66B00ZXjt0YO5KlohRA5SY2XofN4zfuZxLkoj1gXtW8ANNCe9d5Y3eG5eD" crossorigin="anonymous"></script>
</body>
</html>
Result: