Menu items do not toggle

<nav class="navbar fixed-top navbar-expand-lg navbar-dark blue">
<!-- Navbar brand --><a class="navbar-brand" href="#">
<img src="img/BE_Logo.png" alt="Broward Employee"></a>
<!-- Collapse button --><button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#basicExampleNav" aria-controls="basicExampleNav"aria-expanded="false" aria-label="Toggle navigation"><span class="navbar-toggler-icon"></span></button>
<!-- Collapsible content --><div class="collapse navbar-collapse" id="basicExampleNav"><!-- Links --><ul class="navbar-nav mr-auto"><!-- Dropdown --><li class="nav-item dropdown active">
<a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Agencies</a><div class="dropdown-menu dropdown-primary" aria-labelledby="navbarDropdownMenuLink">
<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></li><li class="nav-item">
<a class="nav-link" href="#">County<span class="sr-only">(current)</span></a></li>
<!-- Dropdown -->
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Cyber Security Corner</a>
<div class="dropdown-menu dropdown-primary" aria-labelledby="navbarDropdownMenuLink">
<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>
</li>
<!-- Dropdown --><li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Employee Safety</a>
<div class="dropdown-menu dropdown-primary" aria-labelledby="navbarDropdownMenuLink">
<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>
</li>
<!-- Dropdown -->
<li class="nav-item dropdown"><a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Forms</a><div class="dropdown-menu dropdown-primary" aria-labelledby="navbarDropdownMenuLink"><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></li><!-- Dropdown --><li class="nav-item dropdown"><a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">News</a><div class="dropdown-menu dropdown-primary" aria-labelledby="navbarDropdownMenuLink"><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></li></ul><!-- Links --><form class="form-inline"><div class="md-form my-0"><input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search"></div></form></div><!-- Collapsible content --></nav><!--/.Navbar-->Start your code here

Good morning I am creating a navigation bar but the Dropdown menus are not dropping

Am I doing something wrong?

Thanks