Why is there an error when transferring the service to the controller parameters?

Question

PHP

Tell me why an error occurs when transferring the service to the controller parameters?

use App\Service\CustomService;

// где "...." - в этом месте еще куча разных сервисов подключаются, но они работают
public function index(...., CustomService $customService): Response
{
        $telegramBot = new \TelegramBot\Api\Client($bot->getToken());
        // logic
        $telegramBot->on(function (\TelegramBot\Api\Types\Update $update) use ($telegramBot, $customService) {
                $customService->customMethod(
                        $parametr1 = '...',
                        $parametr2 = '...',
                        $parametr3 = '...',
                );
        }, function () {
            return true;
        });
}

and this is what it says:

request.CRITICAL: Uncaught PHP Exception RuntimeException: "Controller "App\Controller\TestController::index()" requires that you provide a value for the "$customService" argument. Either the argument is nullable and no null value has been provided, no default value has been provided or because there is a non optional argument after this one." at /var/www/project/vendor/symfony/http-kernel/Controller/ArgumentResolver.php line 80 {"exception":"[object] (RuntimeException(code: 0): Controller \"App\\Controller\\TestController ::index()\" requires that you provide a value for the \"$customService\" argument. Either the argument is nullable and no null value has been provided, no default value has been provided or because there is a non optional argument after this one.

How to fix it?

Answer 1

you just had to do cache:clear

Answer 2

index(...., CustomService $customService)

what version of php does this work in?
+ lost the closing bracket of on(