I can not use the bootstrap menu
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="icon" href="imagens/icon-logo-title.png" type="image/png" />
<link rel="shortcut icon" href="imagens/icon-logo-title.png" type="image/png" />
<title>Tleds</title>
<link href="Bootstrap/css/bootstrap.min.css" rel="stylesheet">
</head>
<nav class="navbar navbar-default">
<ul class="navbar-nav ">
<li>
<a href="#"><img src="imagens/icon-logo-64.png"></a>
</li>
<li>
<a href="#">Sobre</a>
</li>
<li>
<a href="#">Serviços</a>
</li>
<li>
<a href="#">Portfólio</a>
</li>
<li>
<a href="#">Contatos</a>
</li>
</ul>
</nav>
<?php require_once('script.php')?>
<!--script.php-->
<script src="Jquery/jquery-3.3.1.min.js"></script>
<script src="Bootstrap/js/bootstrap.min.js"></script>