Once you’ve clicked to ‘Pay’ a bill, it’ll be in ‘Awaiting approval’ status until you approve the payment on your mobile. If you choose not to receive notifications on your iOS device, you can change your notification settings by heading to the in-app Account Switcher, tapping 'Settings’ and then ‘Notifications and Messaging’.
If you can no longer see the notification we sent to your mobile, then wait a few minutes and that bill will go back to Draft status in `Bills to Pay`. You can now attempt to make the payment again.