add a credit card. Because of the two factor requirement, you cannot be charged until you put in a pin. Uber does not ask you for this. It gamifies it so that

add a credit card. Because of the two factor requirement, you cannot be charged until you put in a pin. Uber does not ask you for this. It gamifies it so that the next time you use Uber, it reminds you to first pay the previous bill before you use it again.