You can exit a futures trade on any futures trading platform by the doing the opposite of what you did when entering the trade. If you bought the market you are now "long", so you will need to sell the same number of futures contracts to exit your long position and get "flat" when you have no open positions.
In Trader Talent Pro There is also a button at the top of all ladders that can be used to exit at market and cancel all working orders "Exit at Mkt and Cxl". Tip: This is a helpful tool if you are exiting a position in a “fast market” or if some news or data has been released.
It is always good  practice once you are finished trading for the day, to click the "Exit All Positions Cancel All" button under the Equity tab dropdown. This will ensure any working orders, stops or open positions across your entire system are cancelled and open positions flattened.