navbar.html

<!DOCTYPE html>
<html lang="en">

<head>
   <title>Dropdown Menu Responsive</title>
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <link rel="stylesheet" type="text/css" href="Styles/navbar.css">
</head>

<body>

   <!-- header start -->
   <header class="header">
      <div id="navbar" class="container" >
        
      </div>
   </header>
  

  <!-- <script src="/Scripts/nav.js"></script>  -->
</body>

</html> 

<script type="module">
    import {navbar} from "./Components/mainNavbar.js" ;
let n = document.getElementById("navbar")
n.innerHTML= navbar();
 

</script>
<script type="module" src="./Scripts/navbar.js"></script>