update

resources/views/app.blade.php

@@ -14,7 +14,8 @@
         window.v2board = {
             title: '{{$title}}',
             theme: '{{$theme}}',
-            verison: '{{$verison}}'
+            verison: '{{$verison}}',
+            background_url: '{{$backgroun_url}}'
         }
     </script>
 </head>

routes/web.php

@@ -21,7 +21,8 @@ Route::get('/', function (Request $request) {
     }
     return view('app', [
         'title' => config('v2board.app_name', 'V2Board'),
-        'theme' => config('v2board.app_theme', 1),
+        'theme' => config('v2board.frontend_theme', 1),
+        'backgroun_url' => config('v2board.frontend_url'),
         'verison' => '1.0.2.3'
     ]);
 });