Equity:816.75 - Changes to previous trade, and how to use 'Parent and Contingent' order

I realized the trade which I entered in the previous post has a wrong step for 'Big Shadow' strategy. I was supposed to set Stop Sell below the lowest range of the Candle, instead of selling it at market price. Below is my amended order.

I also spent some panicky time trying to figure out how to use the 'Parent and Contingent' order. I was simply unable to set the Stop Sell just now. In the midst of chatting with an online operator, I found out the reason why.

When I select the 'Parent and Contingent' order, I am supposed to click at the correct spot on the chart! In this case, it is at 0.9213. You are unable to amend the Parent order once you click it on the chart!