lambda function can't access secrets manager

I am developing an AWS Lambda function using Python. When I directly use Python code in AWS Lambda to access the secrets manager, it works fine. However, when I package the Lambda function code with dependencies, upload it as a zip file, and run it, I am unable to retrieve the secret, and the execution times out. Why is this happening?

I have followed the instructions in this link , set up the layer, and ensured that the role and VPC subnet are correctly configured.

============================= after set ENV PARAMETERS_SECRETS_EXTENSION_LOG_LEVEL = debug Debug log

[AWS Parameters and Secrets Lambda Extension] 2023/10/07 08:42:36 INFO Serving on port 2773
EXTENSION	Name: AWSParametersAndSecretsLambdaExtension	State: Ready	Events: [INVOKE, SHUTDOWN]
START RequestId: da2cb206-3ecd-4d68-bc9e-da721a940c83 Version: $LATEST
begin lambda function run
[AWS Parameters and Secrets Lambda Extension] 2023/10/07 08:42:37 INFO ready to serve traffic
2023-10-07T08:43:07.233Z da2cb206-3ecd-4d68-bc9e-da721a940c83 Task timed out after 30.04 seconds

END RequestId: da2cb206-3ecd-4d68-bc9e-da721a940c83
REPORT RequestId: da2cb206-3ecd-4d68-bc9e-da721a940c83	Duration: 30039.07 ms	Billed Duration: 30000 ms	Memory Size: 128 MB	Max Memory Used: 80 MB	Init Duration: 661.31 ms	

and python lambda function code is

import json
import urllib.parse
import boto3
import gzip
import io
import os
import datetime
from datetime import datetime

def get_redshift_credentials():
    try:
        secrets_manager_client = boto3.client('secretsmanager')
        response = secrets_manager_client.get_secret_value(SecretId='this is MY ARN')
        secret_string = response['SecretString']

        secret_data = json.loads(secret_string)

        host = secret_data['host']
        port = secret_data['port']
        dbname = secret_data['dbName']
        user = secret_data['username']
        password = secret_data['password']

        cached_redshift_credentials = (host, port, dbname, user, password)
        return cached_redshift_credentials

    except Exception as e:
        print(f"Error retrieving Redshift credentials: {str(e)}")
        raise



def lambda_handler(event, context):
    print("begin lambda function run")
    redshift_credentials = get_redshift_credentials()
    print(redshift_credentials)