Adding a div affter Ul menu in wordpress meue using navwalker

Question

Hi everyone been away from coding now im learning WordPress, I came a cross bootstrap 5 menu and wanted to converted to wp_menu, basically i want to add an extra div after element the code:

 <nav class="navbar navbar-expand-custom navbar-mainbg">
        <a class="navbar-brand navbar-logo" href="#">Navbar</a>
        <button class="navbar-toggler" type="button" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
        <i class="fa-solid fa-bars fa-lg text-white"></i>
        </button>
        <div class="collapse navbar-collapse" id="navbarSupportedContent">
        <?php 
        wp_nav_menu(
            array(
                'theme_location' => 'top-menu',
                'menu_class'       => 'navbar-nav ml-auto ' ,
                'li_class' => 'nav-item',
                'a_class' => 'nav-link',
                'active_class' => 'active',
                'walker'  => new WP_Bootstrap_Navwalker(), ) );
         
        ?>
        </div>
    </nav>

can anyone tell me what to do to add the <div> immediately after the opening <ul> using items_wrap and close it before the start of the <li> any guidance will be appreciated thank you, i sifted through whole lots of tutorials but no luck so far