This payment mode is only available as a non-integrated payment mode. If you'd like to do quick payments while connected to a POS, use Pay-at-counter.
To make a quick payment in the new payments app:
Tap on New payment
Enter an amount and press Confirm
If tips are enabled, choose to leave a tip or not
If tips are not enabled, you'll be taken straight to the Adyen payments app
Pay
You'll see a success screen
After a few seconds, you'll be auto-redirected back to the Enter amount screen
How to use the new payments app.