Filling default value in forms via relationship

    public static function form(Form $form): Form
    {
        $defaultMenuId = Route::current()->parameter('menu');

        return $form->schema([
            Forms\Components\Card::make([
                Forms\Components\Grid::make()
                    ->relationship('menu')
                    ->columns(0)
                    ->schema([
                        Forms\Components\TextInput::make('title')
                            ->dehydrated(false)     // prevent saving to database
                            ->label('Menu')
                            ->disabled()
                            ->required()
                    ]),
            Forms\Components\Hidden::make('menu_id')
                    ->default($defaultMenuId),

    $category = Category::make(['menu_id' => $defaultMenuId]);
    $category->menu->title;    // and reach title without category created in the database