ordersell 问题

出错信息如下： 2023-02-12 16:57:58 Futures_OKCoin 错误 Sell(21816.29, 5.99): map[code:1 data:[map[clOrdId:9e7f8f03cd7548BCbbc4AC5D4E708813 ordId: sCode:51121 sMsg:Order quantity must be a multiple of the lot size. tag:]] msg:All operations failed] 2023-02-12 16:57:58 信息 amountSell = 5.99 amountBuy= 0 2023-02-12 16:57:54 信息 可卖的比特币量 5.99 2023-02-12 16:57:54 信息 卖价 21814.890000000003 2023-02-12 16:57:54 信息 可买的比特币量 0 2023-02-12 16:57:54 信息 买价 21810.309999999998 2023-02-12 16:57:54 信息 High: 21911.75 Low: 21631.4 Sell: 21816.3 Buy: 21814.3 Last: 21847.6 Volume: 83544 2023-02-12 16:57:54 信息 账户信息 0

代码如下

  exchange.SetDirection("Sell")  
  exchange.Sell(sellPrice,amountSell);
  Log("账户信息",account )
  Log("账户信息",account.Balance )
  ticker1 = exchanges[0].GetTicker() // 首先读取当前行情信息，主要用到最新成交价
  Log("High:", ticker1.High, "Low:", ticker1.Low, "Sell:", ticker1.Sell, "Buy:", ticker1.Buy, "Last:", ticker1.Last, "Volume:", ticker1.Volume)
  Log("买价", buyPrice)
  Log("可买的比特币量", amountBuy )
  Log("卖价",sellPrice)
  Log("可卖的比特币量",amountSell)

是在论坛里看的代码，想试验下。模拟账户里有5.99个BTC 不知道为什么出错啊？ 谢谢