There are two options of how to cancel your order on BeQuant website:
On the main page scroll down to My Orders and Trades section. First tab is Active orders tab, where you can find Cancel buttons on the right side of each order. To see your active orders on all markets, click trading pair on the head of section (i.e. BTC/ETH).
Another option to cancel an order is to proceed to Reports from the main page, "My Orders tab. There you can filter active orders and push Cancel button on the right of the order you wish to cancel.