Have an uber voucher but they still want to charge my card?

I have a work trip coming up and received a voucher to cover my ride expenses. When I go to checkout I see the strikethrough original price and my new price is 0.00. However when I go to confirm and pay, the app requests my Apple Pay. I want to make sure I’m not using my own money, but I’m not sure how to use the voucher. Is this normal?