Added validation part for generate pdf

app/Http/Controllers/PdfController.php

@@ -9,6 +9,7 @@ use App\Models\ProcessOrder;
 use App\Models\StickerStructureDetail;
 use App\Models\User;
 use App\Services\StickerPdfService;
+use Filament\Notifications\Notification;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Log;
 use Illuminate\Support\Facades\Response;
@@ -895,9 +896,21 @@ class PdfController extends Controller
     public function generate(string $stickerId)
     {
 
+        $stickerId = trim($stickerId);
+
         $elements = StickerStructureDetail::where('sticker_id', $stickerId)
             ->first();
 
+        if (!$elements) {
+            Notification::make()
+                ->title('Sticker not found')
+                ->body("Sticker ID '{$stickerId}' does not exist.")
+                ->danger()
+                ->send();
+
+            return;
+        }
+
         $pdfService = new StickerPdfService();
         return $pdfService->generate($stickerId, $elements->toArray());
     }