Nav Menu Class

<?php
function special_nav_class($classes, $item){
    if( in_array('current-menu-item', $classes) ){
        $classes[] = 'active';
    }
    return $classes;
}
add_filter('nav_menu_css_class' , 'special_nav_class' , 10 , 2);


function add_additional_class_on_li($classes, $item, $args) {
    if(isset($args->add_li_class)) {
        $classes[] = $args->add_li_class;
    }
   

 
    return $classes;
}
add_filter('nav_menu_css_class', 'add_additional_class_on_li', 1, 3);


function add_link_atts($atts) {
  $atts['class'] = "nav-link";
  return $atts;
}
add_filter( 'nav_menu_link_attributes', 'add_link_atts');

class My_Walker_Nav_Menu extends Walker_Nav_Menu {
  function start_lvl(&$output, $depth) {
    $indent = str_repeat("\t", $depth);
    $output .= "\n$indent<ul class=\"dropdown-menu\">\n";
  }
}

add_filter( 'nav_menu_link_attributes', 'nav_menu_link_class', 10, 3 );
function nav_menu_link_class( $atts, $item, $args ) {
    $class         = 'dropdown-item';
	$atts['data-bs-toggle']        = 'dropdown';
    $atts['class'] = $class;

    return $atts;
}

?>