async def METHOD_NAME(postgres_connection_string: str) -> AsyncEngine:
    """
    Create a connection of Postgres.
    :param postgres_connection_string: the postgres connection string
    :return: an AsyncEngine object
    """
    if not postgres_connection_string.startswith("postgresql+asyncpg://"):
        logger.critical("Invalid PostgreSQL connection string")
        sys.exit(1)
    logger.info("Connecting to PostgreSQL")
    try:
        pg = create_async_engine(
            postgres_connection_string,
            json_serializer=dump_string,
            json_deserializer=orjson.loads,
            pool_recycle=1800,
        )
        await check_version(pg)
        return pg
    except ConnectionRefusedError:
        logger.critical("Could not connect to PostgreSQL: Connection refused")
        sys.exit(1)