def METHOD_NAME(
    bucket: str, key: str, filename: str, session: Optional[boto3.Session] = None
) -> None:
    """Upload file to S3 bucket."""
    s3_client = _get_client(session)
    LOGGER.info("uploading %s to s3://%s/%s...", filename, bucket, key)
    s3_client.upload_file(Filename=filename, Bucket=bucket, Key=key)