adding hidden column in import - FilamentPhp

i'm using Fiilamentphp for my laravel project, i'm using "filament/filament": "^3.0-stable", and "konnco/filament-import": "^1.6".

I want to add 'created_by' = Auth::id(); to be executed before saving each record.

the code TestImporter.php:

<?php

namespace App\Filament\Imports;

use App\Models\Voucher;
use Filament\Actions\Imports\ImportColumn;
use Filament\Actions\Imports\Importer;
use Filament\Actions\Imports\Models\Import;
class TestImporter extends Importer
{

    protected static ?string $model = Test::class;

    public static function getColumns(): array
    {
        return [
            ImportColumn::make('test_column')
                ->label('Test Column')
                ->requiredMapping(),
            ImportColumn::make('product_id')
                ->label('Product Name')
                ->relationship('product', 'name')
                ->requiredMapping()
                ->example('SUV'),
        ];
    }

    public function resolveRecord(): ?Test
    {
        return new Test();
    }

    public static function getCompletedNotificationBody(Import $import): string
    {
        $body = 'Your test import has completed and ' . number_format($import->successful_rows) . ' ' . str('row')->plural($import->successful_rows) . ' imported.';

        if ($failedRowsCount = $import->getFailedRowsCount()) {
            $body .= ' ' . number_format($failedRowsCount) . ' ' . str('row')->plural($failedRowsCount) . ' failed to import.';
        }

        return $body;
    }
}

How do I add it? I tried adding it to the resolveRecord() and it's not working.

I found a solution but not really convinced by it

public function resolveRecord(): ?Voucher
{
    return new Voucher([
        'serial_voucher' => $this->data['serial_voucher'],
        'product_id' => $this->data['product_id'],
        'created_by' => Auth::id(),
    ]);
}

This made the record to be saved, so the problem solved.