Whenever I reduce the size of my browser, the collapsible navbar in Bootstrap is not visible.
This is the code for my webpage: index.html
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE-edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>My Webpage</title>
<link rel="stylesheet" href="css/bootstrap.min.css">
<link rel="stylesheet" href="css/styles.css">
<link href="https://fonts.googleapis.com/css2?family=Oxygen:wght@300;400;700&display=swap"
rel="stylesheet">
<link href="https://fonts.googleapis.com/css2?family=Lora&display=swap" rel="stylesheet">
</head>
<body>
<header>
<nav id="header-nav" class="navbar navbar-default">
<div class="container">
<div class="navbar-header"> <!--wrapper class-->
<a href="index.html" class="float-left d-none d-md-block">
<div id="logo-img" alt="Logo image"></div>
</a>
<div class="navbar-brand">
<a href="index.html"><h1>Website Name</h1></a>
<p>
<img src="https://img.icons8.com/cotton/64/000000/star.png" alt="Kosher
Certification">
<span>Certified</span>
</p>
</div>
<button class="navbar-toggle collapsed" type="button" data-toggle="collapse" data-
target="#collapsable-nav" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
</div>
</div>
</nav>
</header>
<!-- jQuery (Bootstrap JS plugins depend on it) -->
<script src="js/jquery-3.5.1.min.js"></script>
<script src="js/bootstrap.min.js"></script>
<script src="js/script.js"></script>
</body>
</html>
styles.css
body{
font-size: 16px;
color: #fff;
background-color:#61122f;
font-family: 'Oxygen', sans-serif;
}
#header-nav{
background-color: #f6b319;
border-radius: 0;
border: 0;
}
#logo-img{
background:url("rest.png") no-repeat;
width: 175px;
height: 175px;
margin:10px;
}
.navbar-brand{
padding-top: 25px;
}
.navbar-brand h1{
font-family: 'Lora', serif;
color: #557c3e;
font-size: 1.5em;
text-transform: uppercase;
font-weight: bold;
text-shadow: 1px 1px 1px #222;
margin-top: 0;
margin-bottom: 0;
line-height: .75
}
.navbar-brand a:hover, .navbar-brand a:focus {
text-decoration: none;
}
.navbar-brand p{
color: #000;
text-transform: uppercase;
font-size: .7em;
margin-top: 15px;
}
Upon reducing the page size, the output on the browser looks like this: Browser Output
A small button appears instead of the collapsible navbar. What could be causing this issue?