diff --git a/gemini/client.py b/gemini/client.py
index 43efa15..f169201 100644
--- a/gemini/client.py
+++ b/gemini/client.py
@@ -223,7 +223,7 @@ def _construct_payload(
                                 image
                                 and [
                                     prompt,
-                                    int(os.getenv("GEMINI_ULTRA" or 0)),
+                                    int(os.getenv("GEMINI_ULTRA", "0")),
                                     None,
                                     [[[upload_image(image), 1]]],
                                 ]
diff --git a/gemini/src/model/image.py b/gemini/src/model/image.py
index e0162fd..bc55d77 100644
--- a/gemini/src/model/image.py
+++ b/gemini/src/model/image.py
@@ -50,7 +50,7 @@ def validate_images(cls, images):
                 "Input is empty. Please provide images infomation to proceed."
             )
 
-    # Async downloader
+    # Async
     @classmethod
     async def save(
         cls,
@@ -73,9 +73,33 @@ async def save(
         image_data = await cls.fetch_images_dict(images, cookies)
         await cls.save_images(image_data, save_path)
 
+    # Sync
+    @staticmethod
+    def save_sync(
+        images: List["GeminiImage"],
+        save_path: str = "cached",
+        cookies: Optional[dict] = None,
+    ) -> Optional[Path]:
+        """Synchronously saves the image to the specified path.
+
+        Args:
+            path (str): The directory where the image will be saved.
+            filename (str, optional): The filename for the saved image. If not provided,
+                a filename is generated based on the image title.
+            cookies (dict, optional): Cookies to be used for downloading the image.
+
+        Returns:
+            Optional[Path]: The path where the image is saved, or None if saving fails.
+        """
+        image_data = GeminiImage.fetch_images_dict_sync(images, cookies)
+        GeminiImage.validate_images(image_data)
+        GeminiImage.save_images_sync(image_data, save_path)
+
+    ##### Main functions are above. The code below handles special cases for transmitting byte images.
+
     @staticmethod
     async def fetch_bytes(
-        url: HttpUrl, cookies: Optional[dict] = None
+        url: HttpUrl, cookies: Optional[dict] = None, proxies: Optional[dict] = None
     ) -> Optional[bytes]:
         """
         Fetches bytes of an image asynchronously.
@@ -88,8 +112,8 @@ async def fetch_bytes(
             Optional[bytes]: The bytes of the image, or None if fetching fails.
         """
         try:
-            async with httpx.AsyncClient(follow_redirects=True) as client:
-                response = await client.get(str(url), cookies=cookies)
+            async with httpx.AsyncClient(follow_redirects=True, cookies=cookies, proxies=proxies) as client:
+                response = await client.get(str(url))
                 response.raise_for_status()
                 return response.content
         except Exception as e:
@@ -136,28 +160,6 @@ async def save_images(image_data: Dict[str, bytes], save_path: str = "cached"):
             except Exception as e:
                 print(f"Error saving {title}: {str(e)}")
 
-    # Sync downloader
-    @staticmethod
-    def save_sync(
-        images: List["GeminiImage"],
-        cookies: Optional[dict] = None,
-        save_path: str = "cached",
-    ) -> Optional[Path]:
-        """Synchronously saves the image to the specified path.
-
-        Args:
-            path (str): The directory where the image will be saved.
-            filename (str, optional): The filename for the saved image. If not provided,
-                a filename is generated based on the image title.
-            cookies (dict, optional): Cookies to be used for downloading the image.
-
-        Returns:
-            Optional[Path]: The path where the image is saved, or None if saving fails.
-        """
-        image_data = GeminiImage.fetch_images_dict_sync(images, cookies)
-        GeminiImage.validate_images(image_data)
-        GeminiImage.save_images_sync(image_data, save_path)
-
     @staticmethod
     def fetch_bytes_sync(
         url: HttpUrl, cookies: Optional[dict] = None
diff --git a/gemini/src/model/parser/response_parser.py b/gemini/src/model/parser/response_parser.py
index 0a8335d..8010887 100644
--- a/gemini/src/model/parser/response_parser.py
+++ b/gemini/src/model/parser/response_parser.py
@@ -91,7 +91,7 @@ def _extract_body(self, response_text: str) -> Dict:
                 continue
 
         raise ValueError(
-            "All parsing strategies failed. Try to use `Gemini.send_request(prompt)` to get original payload."
+            "Google PeerSide authentication may have expired. Refresh the cookie manually and retry the test.\nDetails: All parsing strategies failed. Try to use `Gemini.send_request(prompt)` to get original payload"
         )
 
     def __extract_strategy_1(self, response_text: str) -> Dict: