akaunting/app/Http/Requests/Document/DocumentAddItem.php

<?php

namespace App\Http\Requests\Document;

use App\Abstracts\Http\FormRequest;

class DocumentAddItem extends FormRequest
{
    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'item_row' => 'required|integer',
            'currency_code' => 'required|string|currency',
        ];
    }
}