fix(kb): add from bytes (#187)

Author: zakahan

veadk/knowledgebase/backends/vikingdb_knowledge_backend.py

@@ -195,7 +195,7 @@ def add_from_bytes(self, content: bytes, file_name: str, **kwargs) -> bool:
                 - tos_bucket_path: str, the path of TOS bucket
         """
         tos_bucket_name, tos_bucket_path = _extract_tos_attributes(**kwargs)
-        tos_url = _upload_bytes_to_tos(
+        tos_url = self._upload_bytes_to_tos(
             content,
             tos_bucket_name=tos_bucket_name,
             object_key=f"{tos_bucket_path}/{file_name}",