HTML

html place div on background image

<!-- HTML -->
<header>
        <nav>
            <ul>
            <li><a href="Menu.html" style="padding: 0 20px 0 20px;">Menu</a></li>
            <li><a href="Burritos.html" style="padding: 0 20px 0 20px;">Burritos</a></li>
                <li><a href="index.html"><img class="header-image" src="assets/Headerlogo1.png"></a></li>
            <li><a href="Contact.html" style="padding: 0 20px 0 20px;">Contact Us</a></li>
            <li><a href="About.html" style="padding: 0 20px 0 20px;">About Us</a></li>   
            </ul>
        </nav>
  
    	<div id="wrapper"></div>
</header> 

<!-- CSS -->
<style>
        header {
            background-image: url(img/your-img.jpg);
            background-size: cover;
            background-position: center;
            height: 100vh; /* or whatever you wish */
            background-attachment: fixed;
            position: relative;
        }

        .wrapper {
            position: absolute;
            width: 1140px; /* or how much do you want */
            top: 50%;
            left: 50%;
            -webkit-transform: translate(-50%, -50%);
            -ms-transform: translate(-50%, -50%);
            transform: translate(-50%, -50%);
        }
 </style>