How can I add title and sum value of column in laravel excel version 3?

I get reference from here : https://laravel-excel.maatwebsite.nl/docs/3.0/getting-started/basics

So I use version 3

My controller like this :

public function exportToExcel(Request $request)
{
    $data = $request->all();
    $exporter = app()->makeWith(SummaryExport::class, compact('data'));   
    return $exporter->download('Summary.xlsx');
}

My script export to excel like this :

namespace App\Exports;
use App\Repositories\ItemRepository;
use Maatwebsite\Excel\Concerns\FromCollection;
use Maatwebsite\Excel\Concerns\Exportable;
use Maatwebsite\Excel\Concerns\WithHeadings;
class SummaryExport implements FromCollection, WithHeadings {
    use Exportable;
    protected $itemRepository;
    protected $data;
    public function __construct(ItemRepository $itemRepository, $data) {
        $this->itemRepository = $itemRepository;
        $this->data = $data;
    }
    public function collection()
    {
        $items = $this->itemRepository->getSummary($this->data);
        return $items;
    }
    public function headings(): array
    {
        return [
            'No',
            'Item Number',
            'Sold Quantity',
            'Profit'
        ];
    }
}

If the script executed, the result like this :

I want to add some description or title above the table and I want to sum sold quantity column and profit column

So I want the result like this :

I had read the documentation and search in the google, but I don't find the solution

Is there anyone who can help?

via Chebli Mohamed