You can cancel orders as long as they are not settled.
To view and cancel any Pending orders:
Log into the Douugh app (or tap the ‘Home’ button if you are already logged in).
Tap 'Invest Jar’.
Tap ‘US Shares’.
Tap ‘Pending Orders’.
Tap the order you wish to cancel and tap ‘Cancel’.
After confirming your choice, the order will no longer be executed.