protected $middleware = [
'Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode',
'Illuminate\Cookie\Middleware\EncryptCookies',
'Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse',
'Illuminate\Session\Middleware\StartSession',
'Illuminate\View\Middleware\ShareErrorsFromSession',
'App\Http\Middleware\VerifyCsrfToken',
'App\Http\Middleware\Authenticate',// add this line according to your namespace
];
it will redirect the user if not logged in. UPDATE Keep in mind that adding auth middleware as global will create redirect loop so avoid it.
Or if you want specific routes to be protected then attach the middleware auth to that route
Route::get('admin/profile', ['middleware' => 'auth', function () {
//
}]);