No log groups or logs in Cloudwatch after sending data via Watchtower

I am trying to use the watchtower API to send logs to Cloudwatch - but I don't see any log groups or any data.

Here is the relevant python code. Am I instantiating the Cloudwatch handler correctly?

fwiw, under IncomingLogEvents: Sum, I do see that CloudWatch has gotten the logs! But I do not have any LogGroups at all.

Thanks.

class FileOps:
    def __init__(self):
        load_dotenv()
        self._service_name = "s3"
        self._region_name = os.getenv("AWS_REGION")
        self._aws_access_key_id = os.getenv("AWS_ACCESS_KEY_ID")
        self._secret_access_key = os.getenv("AWS_SECRET_ACCESS_KEY")
        self._endpoint_url = f"https://s3.{self._region_name}.amazonaws.com"
        self._session = self.get_thread_safe_s3_session()

        # Set up basic logging configuration
        logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
        self.logger = logging.getLogger(__name__)

        # Initialize CloudWatch handler
        self.initialize_cloudwatch_handler(self.logger)

    def get_cloudwatch_logs_client(self) -> Any:
        session = self.get_thread_safe_s3_session()
        client = session.client(
            "logs",
            region_name=self._region_name
        )
        return client

    def initialize_cloudwatch_handler(self, logger):
        # Set up CloudWatch handler
        cloudwatch_handler = watchtower.CloudWatchLogHandler(
            log_group=os.getenv("CLOUDWATCH_TIINGO_LOG_GROUP"),
            stream_name="TiingoSoraStocks-{strftime:%Y-%m-%d}",
            use_queues=True,  # Set to True for better performance in production
            boto3_client=self.get_cloudwatch_logs_client(),
            create_log_group=True
        )

        # Add CloudWatch handler to the logger
        logger.addHandler(cloudwatch_handler)