There are 2 ways a passenger can pay the driver.
1. The first and still most popular is simply by cash. Passenger and driver can use the suggested price from the app or negotiate a fairer price (if there are tolls for example) and the payment is made at the end of the ride in person.
2. The Wunder Wallet is the easiest option. This feature was introduced to provide cashless payments which can make life a lot easier. You will know if a user will pay using the Wallet because they'll have a green wallet icon next to their avatar, as below. When the ride is completed in the app, the funds will be transferred from passengers wallet to drivers wallet. No need to worry about having the correct cash on you!
The most important thing is that both passenger and driver are clear and happy with the arrangement. Chat together, politely and in a friendly way and we can make Wunder a community we're all proud to be a part of!