region --> region_name

app.py

@@ -38,7 +38,7 @@ def select_foundation_model(model_name: str, max_new_tokens: int) -> LLM:
         )
     elif model_name in {"claude-3.5-haiku", "llama-3.1-70b-instruct", "mistral-large", "mixtral-8x7B"}:
         llm = ChatBedrock(
-            client=boto3.client("bedrock-runtime", region="us-east-1"),
+            client=boto3.client("bedrock-runtime", region_name="us-east-1"),
             model=Name2Endpoint[model_name],
             max_tokens=max_new_tokens,
             temperature=0.0