The pickup and return points are shown in the app and on the booking page before you book.
Return the car to the drop-off area of your booking, or to an allowed drop-off area shown in the app. Don't leave it in private parking or behind barriers unless the app lists that place. Where the operator allows a return outside the drop-off area, a fee applies, and the app shows it before you end the rental.
The exact rules are in the Terms of Service and your operator's rental terms.