diff --git a/camel/model_backend.py b/camel/model_backend.py
index e6be3a12e..c9f42472d 100644
--- a/camel/model_backend.py
+++ b/camel/model_backend.py
@@ -13,6 +13,8 @@
 # =========== Copyright 2023 @ CAMEL-AI.org. All Rights Reserved. ===========
 from abc import ABC, abstractmethod
 from typing import Any, Dict
+import os
+import time
 
 import openai
 import tiktoken
@@ -69,8 +71,10 @@ def run(self, *args, **kwargs) -> Dict[str, Any]:
         num_max_token = num_max_token_map[self.model_type.value]
         num_max_completion_tokens = num_max_token - num_prompt_tokens
         self.model_config_dict['max_tokens'] = num_max_completion_tokens
+        time.sleep(0.1)
         response = openai.ChatCompletion.create(*args, **kwargs,
                                                 model=self.model_type.value,
+                                                engine=os.getenv("OPENAI_API_ENGINE"),
                                                 **self.model_config_dict)
         cost = prompt_cost(
                 self.model_type.value,