Yes. Open positions are visible on the Positions screen, under Trades option in the menu. You can tap on the open position you want to close and choose exit option to close the trade. If your positions book has only open positions of one strategy, then you can choose Close All option to exit all legs together. This ensures you close the full structure simultaneously rather than legging out manually, which could expose you to unintended directional risk between exits.  However, if you have other open positions too, then you will have to manually close each leg. 

Exiting all legs together also ensures you realise the full strategy P&L at the time of exit, rather than partial P&L from individual legs.