Laravel API 404 error

I am making simple API with Laravel 5.4 and I have problem. I created routing and some data for tests but when I testing if routing work properly with Postman by putting localhost:8888/{projectname}/api/v1/meeting it shows me error 404 page not found. What am I doing wrong?

routes/api.php

<?php    
Route::group(['prefix' => 'v1'], function() {
    Route::resource('meeting', 'MeetingController', [
        'except' => ['edit', 'create']
    ]);

    Route::resource('meeting/registration', 'RegistrationController', [
        'only' => ['store', 'destroy']
    ]);

    Route::post('user', [
        'uses' => 'AuthController@store'
    ]);

    Route::post('user/signin', [
        'uses' => 'AuthController@signin'
    ]);
});

MeetingController

<?php    
namespace App\Http\Controllers;    
use Illuminate\Http\Request;    
use App\Http\Requests;    
class MeetingController extends Controller
{
    public function __construct()
    {
        // $this->middleware('name');
    }

    public function index()
    {
        return "It works!";
    }

    public function store(Request $request)
    {
        return "It works!";
    }

    public function show($id)
    {
        return "It works!";
    }

    public function update(Request $request, $id)
    {
        return "It works!";
    }

    public function destroy($id)
    {
        return "It works!";
    }

}

RegistrationController

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Http\Requests;

class RegistrationController extends Controller
{
    public function store(Request $request)
    {
        return "It works!";
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int $id
     * @return \Illuminate\Http\Response
     */
    public function destroy($id)
    {
        return "It works!";
    }
}

AuthController

    <?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Http\Requests;

class AuthController extends Controller
{
    public function store(Request $request)
    {
        return "It works!";
    }

    public function signin(Request $request)
    {
        return "It works!";
    }
}

Output of command php artisan route:list:

    +--------+-----------+--------------------------------------------+----------------------+-----------------------------------------------------+------------+
| Domain | Method    | URI                                        | Name                 | Action                                              | Middleware |
+--------+-----------+--------------------------------------------+----------------------+-----------------------------------------------------+------------+
|        | GET|HEAD  | /                                          |                      | Closure                                             | web        |
|        | POST      | api/v1/meeting                             | meeting.store        | App\Http\Controllers\MeetingController@store        | api        |
|        | GET|HEAD  | api/v1/meeting                             | meeting.index        | App\Http\Controllers\MeetingController@index        | api        |
|        | POST      | api/v1/meeting/registration                | registration.store   | App\Http\Controllers\RegistrationController@store   | api        |
|        | DELETE    | api/v1/meeting/registration/{registration} | registration.destroy | App\Http\Controllers\RegistrationController@destroy | api        |
|        | DELETE    | api/v1/meeting/{meeting}                   | meeting.destroy      | App\Http\Controllers\MeetingController@destroy      | api        |
|        | PUT|PATCH | api/v1/meeting/{meeting}                   | meeting.update       | App\Http\Controllers\MeetingController@update       | api        |
|        | GET|HEAD  | api/v1/meeting/{meeting}                   | meeting.show         | App\Http\Controllers\MeetingController@show         | api        |
|        | POST      | api/v1/user                                |                      | App\Http\Controllers\AuthController@store           | api        |
|        | POST      | api/v1/user/signin                         |                      | App\Http\Controllers\AuthController@signin          | api        |
+--------+-----------+--------------------------------------------+----------------------+-----------------------------------------------------+------------+

In Laravel 5.4, your routes/api.php should look like this:

<?php

Route::prefix('v1')->group(function () {
    Route::resource('meeting', 'MeetingController', [
        'except' => ['edit', 'create']
    ]);

    Route::resource('meeting/registration', 'RegistrationController', [
        'only' => ['store', 'destroy']
    ]);

    Route::post('user', [
        'uses' => 'AuthController@store'
    ]);

    Route::post('user/signin', [
        'uses' => 'AuthController@signin'
    ]);
});

For more info, visit their docs here.