Tweak default files.

app/Providers/RouteServiceProvider.php

@@ -68,7 +68,9 @@ class RouteServiceProvider extends ServiceProvider
     protected function mapApiRoutes()
     {
         Route::group([
-            'namespace' => $this->namespace, 'middleware' => 'api',
+            'middleware' => ['api', 'auth:api'],
+            'namespace' => $this->namespace,
+            'prefix' => 'api',
         ], function ($router) {
             require base_path('routes/api.php');
         });

routes/api.php

 <?php
 
+use Illuminate\Http\Request;
+
 /*
 |--------------------------------------------------------------------------
 | API Routes
@@ -11,9 +13,6 @@
 |
 */
 
-Route::group([
-    'prefix' => 'api',
-    'middleware' => 'auth:api',
-], function () {
-    //
+Route::get('/user', function (Request $request) {
+    return $request->user();
 });