When you tap on the "Drop-off Passenger" button, you can get the payment from the passenger. Don’t forget to add the additional charges during the trip under “Tolls & Others” and make sure to enter the correct amount in the field.
For Cash bookings, you can collect cash directly from the passenger. If the passenger already left and you forgot to collect the amount, the Grab system has no capability to collect the amount for you.
For GrabPay bookings, the passenger will automatically be charged on their GrabPay account so no need to collect cash from them.