fix(api): Add error handling for item not found

app.py

@@ -203,6 +203,9 @@ def add():
         spider = BarcodeSpider(x_rapidapi_key=X_RapidAPI_Key)
 
         good = spider.get_good(barcode)
+        if not good:
+            response_data = {"message": "Item not found"}
+            return jsonify(response_data), 400
         try:
             if add_product(good, location):
                 response_data = {"message": "New item added successfully"}