A currency order can be created from the Accounts tab, by clicking '...' (next to 'Add money') and then choosing 'Exchange'.
Alternatively from the star Icon on the top right of the Home and the Wealth tab, opening the Favourites screen, then choosing Orders, and tapping on Add New.
Your created currencies orders can be then found in 'Orders' tab. You will be able to see both pending and executed orders.
To cancel a currency order, please access the Orders list. There, you can either swipe on a pending order to access the delete action or tap on it: the order summary screen will open and you will get access to a delete button.