Laravel 5.2 ErrorException Undefined index: username

I followed this guide " link " to make the connection ldap with laravel and postgres but when I write The name of user and the password on the page, shows me this error and I have no idea what to do. Any idea what it could be?

This is the error of the page:

ErrorException in Resolver.php line 46:
Undefined index: username

    in Resolver.php line 46
    at HandleExceptions->handleError('8', 'Undefined index: username', 'D:\APPS\Xampp\htdocs\secantv-app\vendor\adldap2\adldap2-laravel\src\Auth\Resolver.php', '46', array('credentials' => array('email' => null, 'password' => 'password'))) in Resolver.php line 46
    at Resolver->byCredentials(array('email' => null, 'password' => 'password')) in DatabaseUserProvider.php line 105
    at DatabaseUserProvider->retrieveByCredentials(array('email' => null, 'password' => 'password')) in SessionGuard.php line 353
    at SessionGuard->attempt(array('email' => null, 'password' => 'password'), false) in AuthenticatesUsers.php line 74
    at AuthController->login(object(Request))
    at call_user_func_array(array(object(AuthController), 'login'), array(object(Request))) in Controller.php line 80
    at Controller->callAction('login', array(object(Request))) in ControllerDispatcher.php line 146
    at ControllerDispatcher->call(object(AuthController), object(Route), 'login') in ControllerDispatcher.php line 94
    at ControllerDispatcher->Illuminate\Routing\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in RedirectIfAuthenticated.php line 24
    at RedirectIfAuthenticated->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(RedirectIfAuthenticated), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
    at Pipeline->then(object(Closure)) in ControllerDispatcher.php line 96
    at ControllerDispatcher->callWithinStack(object(AuthController), object(Route), object(Request), 'login') in ControllerDispatcher.php line 54
    at ControllerDispatcher->dispatch(object(Route), object(Request), 'App\Http\Controllers\Auth\AuthController', 'login') in Route.php line 174
    at Route->runController(object(Request)) in Route.php line 140
    at Route->run(object(Request)) in Router.php line 724
    at Router->Illuminate\Routing\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in VerifyCsrfToken.php line 64
    at VerifyCsrfToken->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(VerifyCsrfToken), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in ShareErrorsFromSession.php line 49
    at ShareErrorsFromSession->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(ShareErrorsFromSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in StartSession.php line 64
    at StartSession->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(StartSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in AddQueuedCookiesToResponse.php line 37
    at AddQueuedCookiesToResponse->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(AddQueuedCookiesToResponse), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in EncryptCookies.php line 59
    at EncryptCookies->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(EncryptCookies), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
    at Pipeline->then(object(Closure)) in Router.php line 726
    at Router->runRouteWithinStack(object(Route), object(Request)) in Router.php line 699
    at Router->dispatchToRoute(object(Request)) in Router.php line 675
    at Router->dispatch(object(Request)) in Kernel.php line 246
    at Kernel->Illuminate\Foundation\Http\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in Debugbar.php line 51
    at Debugbar->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(Debugbar), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in CheckForMaintenanceMode.php line 44
    at CheckForMaintenanceMode->handle(object(Request), object(Closure))
    at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
    at Pipeline->Illuminate\Routing\{closure}(object(Request))
    at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
    at Pipeline->then(object(Closure)) in Kernel.php line 132
    at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 99
    at Kernel->handle(object(Request)) in index.php line 50
    at require_once('D:\APPS\Xampp\htdocs\secantv-app\public\index.php') in server.php line 21