Add arrows to the nav

<?php

function yourprefix_menu_arrow($item_output, $item, $depth, $args) {
    if (in_array('menu-item-has-children', $item->classes)) {
        $arrow = '
        <div class="nav-arrow">
            <svg fill="#8198b8" width="100pt" height="100pt" version="1.1" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
             <path d="m79.699 43.5-5.6992-5.6016-23.801 24.301-24.301-23.801-5.5977 5.8008 30.098 29.301z" fill="#8198b8"/>
            </svg>
        </div>'; // Change the class to your font icon
        $item_output = str_replace('</a>', '</a>'. $arrow .'', $item_output);
    }
    return $item_output;
}
add_filter('walker_nav_menu_start_el', 'yourprefix_menu_arrow', 10, 4);

?>

<?php wp_nav_menu( array(
   'menu' => 'main',
   'container' => 'nav',
   'container_class' => 'nav',
   'menu_class' => 'list'
 )); ?>