code: def placeOrder(self, contract, order, orderId=None, account=None):
          
  
          # get latest order id before submitting an order
          self.requestOrderIds()
  
          # continue...
          useOrderId = self.orderId if orderId == None else orderId
          if account:
              order.m_account = account
          self.ibConn.placeOrder(useOrderId, contract, order)
  
          account_key = order.m_account
          self.orders[useOrderId] = {
              "id":       useOrderId,
              "symbol":   self.contractString(contract),
              "contract": contract,
              "status":   "SENT",
              "reason":   None,
              "avgFillPrice": 0.,
              "parentId": 0,
              "time": datetime.fromtimestamp(int(self.time)),
              "account": None
          }
          if hasattr(order, "m_account"):
              self.orders[useOrderId]["account"] = order.m_account
  
          # return order id
          return useOrderId
docs: Place order on IB TWS