How can I get the name of the lambda function that raised error with DLQ?

LambdaA is a function that raises an error.

import json

def lambda_handler(event, context):
    raise Exception("ERROR!!")
    return {
        'statusCode': 200,
        'body': json.dumps('Hello from Lambda!')
    }

LambdaB is a function that prints "event".

import json

def lambda_handler(event, context):
    print(f"Event: {event}")
    return {
        'statusCode': 200,
        'body': json.dumps('Hello from Lambda!')
    }

The SNS topic "TestTopic" is set as Dead-letter queue service in the LambdaA .
"TestTopic" is subscribed by LambdaB.

I invoked LambdaA asynchronously and checked the CloudWatch logs for LambdaB.
And then "event" dose not seem to contain the function name that caused the error.

Event: {'Records': [{'EventSource': 'aws:sns', 'EventVersion': '1.0', 'EventSubscriptionArn': 'arn:aws:sns:ap-northeast-1:xxxxxxxxxxxx:TestTopic:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx', 'Sns': {'Type': 'Notification', 'MessageId': 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx', 'TopicArn': 'arn:aws:sns:ap-northeast-1:xxxxxxxxxxxx:TestTopic', 'Subject': None, 'Message': '{}', 'Timestamp': '2024-03-15T10:26:25.862Z', 'SignatureVersion': '1', 'Signature': 'xxxxxxxxxxxxxxxxxxx', 'SigningCertUrl': 'https://sns.ap-northeast-1.amazonaws.com/SimpleNotificationService-xxxxxxxxxxxxxxxxxxxx.pem', 'UnsubscribeUrl': 'https://sns.ap-northeast-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:ap-northeast-1:xxxxxxxxxxxx:TestTopic:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx', 'MessageAttributes': {'RequestID': {'Type': 'String', 'Value': 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'}, 'ErrorCode': {'Type': 'String', 'Value': '200'}, 'ErrorMessage': {'Type': 'String', 'Value': 'ERROR!!'}}}}]}

How can I get the function name?