The "Pair & Pay" feature allows you to use Curb to pay for a taxi ride you hail on the street. When you get in the cab, tap the "Pair & Pay" button. You will be prompted to enter the 7-digit code that appears on the screen in the backseat of the cab. Once pairing is successful, your payment will be processed automatically at the end of the ride, just like a Curb ride you book with the app.
At this time "Pair & Pay" may not be available in all vehicles. If you do not see a 7-digit code on the backseat screen, you cannot use Curb to pay. You should pay your driver using cash or with a credit card swiped in the taxi at the end of the ride.