请问etrade怎么卖fractional share啊？好像只能卖整数的股票？

我有一些股票有divident reinvest那种所以有fractional shares。我已经把整数的share都卖了，就剩0.77share了，卖的时候用market order提示必须是closing sell order，
Orders containing fractional shares must be entered as a closing sell order for the full fractional (decimal) quantity owned. Please edit your quantity and resubmit your order.

不明白啥意思，然后把market order改成market on close又提示必须用market order，

Orders with fractional quantities must be entered as Market or Limit orders, and must be entered as a Market order if the quantity is less than one share. Please edit your Price Type, or if your quantity is greater than 1 you can submit a separate order for the fractional (decimal) quantity. Orders for less than one share will not be charged commissions.

怎么都卖不掉。大家都是怎么操作的？