Changed to topic link

app/Http/Controllers/TopicsController.php

@@ -29,7 +29,7 @@ class TopicsController extends Controller
     public function show(Topic $topic) : JsonResponse
     {
         return response()->json([
-            'topic' => $topic,
+            'topic' => new TopicResource($topic),
             'articles' => $topic->articles()->paginate(8)
         ]);
     }

app/Http/Resources/TopicResource.php

@@ -17,7 +17,7 @@ class TopicResource extends JsonResource
         return [
             "name" => $this->name,
             "slug" => $this->slug,
-            "url" => url(route('topics.show', $this->slug))
+            "link" => url(route('topics.show', $this->slug))
         ];
     }
 }