Kirby 4 Panel Menu

config.php

<?php

use App\Menu;

return [
    'panel.menu' => [
        'site' => Menu::site('Overview'),
        '-',
        'magazine' => Menu::page('Magazine', 'magazine', 'pages/magazine'),
        'trips'    => Menu::page('Trips', 'trips', 'pages/trips'),
        'service'  => Menu::page('Service', 'service', 'pages/service'),
        '-',
        'uploads' => Menu::page('Uploads', 'uploads', 'pages/uploads'),
        'users',
        '-',
        'languages',
        'system',
    ],
];

Menu.php

<?php

namespace App;

use Closure;
use Kirby\Cms\App;

class Menu
{
    public static array $pages = [];

    public static string $path;

    public static function path(): string
    {
        return static::$path ??= App::instance()->request()->path()->toString();
    }

    public static function page(string $label, string $icon = null, string $link = null, Closure|bool $current = null): array
    {
        return static::$pages[] = [
            'label'   => $label,
            'link'    => $link,
            'icon'    => $icon,
            'current' => $current ?? fn () =>
                str_contains(static::path(), $link)
        ];
    }

    public static function site(string $label, string $icon = 'home'): array
    {
        return [
            'label'   => $label,
            'current' => function (string $id = null) {
                if ($id !== 'site') {
                    return false;
                }

                foreach (static::$pages as &$page) {
                    if (str_contains(static::path(), $page['link'])) {
                        return false;
                    }
                }

                return true;
            },
        ];
    }
}