Missing argument 1 for MyController in RESTful application

I am developing app in laravel (REST server), using Basic Auth. Using Postman, all GET requests I have implemented seem to work, but unfortunately POST requests not.

routes.php:

Route::post('my/action', 'MyController@postMyAction');

My Controller:

public function __construct()
{
    $this->middleware('auth.basic.once');
}

public function postMyAction($request)
{
    // some logic here
}

The problem is, that this way, after setting credentials and some params in Postman, following exception appears:

Missing argument 1 for App\Http\Controllers\MyController::postMyAction()

Does anybody knows how to put request into post-processing function defined in routes?

Thanks in advance.

via Chebli Mohamed