How I can place order through this code :def order(self, 
              symbol:            str, 
              price:             float, 
              vol:               float, 
              side:              int, 
              type:              int, 
              open_type:         int, 
              position_id:       Optional[int]   = None, 
              leverage:          Optional[int]   = None, 
              external_oid:      Optional[str]   = None, 
              stop_loss_price:   Optional[float] = None, 
              take_profit_price: Optional[float] = None, 
              position_mode:     Optional[int]   = None, 
              reduce_only:       Optional[bool]  = False) -> dict:
        """
        ### Order (Under maintenance)
        #### Required permissions: Trading permission

        Rate limit: 20 times / 2 seconds

        https://mxcdevelop.github.io/apidocs/contract_v1_en/#order-under-maintenance

        :param symbol: the name of the contract
        :type symbol: str
        :param price: price
        :type price: decimal
        :param vol: volume
        :type vol: decimal
        :param leverage: (optional) leverage, Leverage is necessary on Isolated Margin
        :type leverage: int
        :param side: order direction 1 open long ,2close short,3open short ,4 close l
        :type side: int
        :param type: orderType,1:price limited order,2:Post Only Maker,3:transact or cancel instantly ,4 : transact completely or cancel completely，5:market orders,6 convert market price to current price
        :type type: int
        :param openType: open type,1:isolated,2:cross
        :type openType: int
        :param positionId: (optional) position Id, It is recommended to fill in this parameter when closing a position
        :type positionId: long
        :param externalOid: (optional) external order ID
        :type externalOid: str
        :param stopLossPrice: (optional) stop-loss price
        :type stopLossPrice: decimal
        :param takeProfitPrice: (optional) take-profit price
        :type takeProfitPrice: decimal
        :param positionMode: (optional) position mode,1:hedge,2:one-way,default: the user's current config
        :type positionMode: int
        :param reduceOnly: (optional) Default false,For one-way positions, if you need to only reduce positions, pass in true, and two-way positions will not accept this parameter.
        :type reduceOnly: bool

        :return: response dictionary
        :rtype: dict
        """
        return self.call("POST", "api/v1/private/order/submit",
                            params = dict(
                                    symbol = symbol,
                                    price = price,
                                    vol = vol,
                                    side = side,
                                    type = type,
                                    openType = open_type,
                                    positionId = position_id,
                                    leverage = leverage,
                                    externalOid = external_oid,
                                    stopLossPrice = stop_loss_price,
                                    takeProfitPrice = take_profit_price,
                                    positionMode = position_mode,
                                    reduceOnly = reduce_only
                            ))