Can not get Request data in custom service?

I have custom service:

<?php
namespace App\Library\Services;

use Illuminate\Http\Request;

class RegisterCustomerService
{

    private $request;

    public function constructor(Request $request)
    {

        $this->request = $request;
    }

    public function register($role)
    {

        dd($this->request);

     }

}

Why I can not get dd($this->request); when I do POST request:

$customer = $registerCustomerService->register('customer');

via Chebli Mohamed