applicant-site/app/Http/Requests/admin/Catalog/StoreDepartmentRequest.php

<?php

namespace App\Http\Requests\admin\Catalog;

use Illuminate\Contracts\Validation\ValidationRule;
use Illuminate\Foundation\Http\FormRequest;

class StoreDepartmentRequest extends FormRequest
{
    public function authorize(): bool
    {
        return true;
    }

    public function rules(): array
    {
        return [
            'position' => 'required|int|max:255',
            'name' => 'required|string|max:255|unique:educational_institutions,name',
            'description' => 'string',
            'slug' => 'required|string',
            'faculty_id' => 'required|int',
        ];
    }
}