Yes, depending on your level of access, you can cancel Direct Debits set up on your accounts.
On the account details screen, find the account the Direct Debit is paid from and select ‘More’ and ‘Direct Debits’. Then open the Direct Debit you want to cancel and select ‘Delete’. Once it’s cancelled, you can only set it up again by contacting the company you’re paying and completing a new Direct Debit instruction.
It’s possible the next payment will still be made even after you’ve cancelled it. This depends on when the next payment is due to be processed. You’ll see a message to let you know if this applies.