Navbar (Collapse) doesn't work Bootstrap 5
The narbar(collapse) button doesn't on my pc, the button still show up, but it doesn't show the navbar when I click the button. However, when I post the code on codeply2 (without Link to bootsrap5 and sources) the button work perfect. I think the poblem is at the Link and Sources, but I don't know how to fix it.
<head>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-primary ">
<a class="navbar-brand ps-2" href="#">ICat</a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarTogglerDemo01" aria-controls="navbarTogglerDemo01" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarTogglerDemo01">
<ul class="navbar-nav ms-auto pe-5">
<li class="nav-item"><a class="nav-link" href="">Home</a></li>
<li class="nav-item"><a class="nav-link" href="">Contact</a></li>
<li class="nav-item"><a class="nav-link" href="">Fan Page</a></li>
<li class="nav-item"><a class="nav-link" href="">Product</a></li>
</ul>
</div>
</nav>
</body>I updated your code now it's working.
your bootstrap 5 CSS reference is right but the JS reference is wrong you have to put this js bootstrap cnd for JS <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.1.3/js/bootstrap.min.js" integrity="sha512-OvBgP9A2JBgiRad/mM36mkzXSXaJE9BEIENnVEmeZdITvwT09xnxLtT4twkCa8m/loMbPHsvPl0T8lRGVBwjlQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
<head>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.1.3/js/bootstrap.min.js" integrity="sha512-OvBgP9A2JBgiRad/mM36mkzXSXaJE9BEIENnVEmeZdITvwT09xnxLtT4twkCa8m/loMbPHsvPl0T8lRGVBwjlQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-primary ">
<a class="navbar-brand ps-2" href="#">ICat</a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarTogglerDemo01" aria-controls="navbarTogglerDemo01" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarTogglerDemo01">
<ul class="navbar-nav ms-auto pe-5">
<li class="nav-item"><a class="nav-link" href="">Home</a></li>
<li class="nav-item"><a class="nav-link" href="">Contact</a></li>
<li class="nav-item"><a class="nav-link" href="">Fan Page</a></li>
<li class="nav-item"><a class="nav-link" href="">Product</a></li>
</ul>
</div>
</nav>
</body><!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- Bootstrap CSS -->
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<title>Hello, world!</title>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-primary ">
<a class="navbar-brand ps-2" href="#">ICat</a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarTogglerDemo01" aria-controls="navbarTogglerDemo01" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarTogglerDemo01">
<ul class="navbar-nav ms-auto pe-5">
<li class="nav-item"><a class="nav-link" href="">Home</a></li>
<li class="nav-item"><a class="nav-link" href="">Contact</a></li>
<li class="nav-item"><a class="nav-link" href="">Fan Page</a></li>
<li class="nav-item"><a class="nav-link" href="">Product</a></li>
</ul>
</div>
</nav>
<!-- Option 1: Bootstrap Bundle with Popper --> <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ka7Sk0Gln4gmtz2MlQnikT1wXgYsOg+OMhuP+IlRH9sENBO0LRn5q+8nbTov4+1p" crossorigin="anonymous"></script>
</body>
</html>Put a script tag always inside the bottom of the body tag.