Returning empty carts

Just curious for whoever is willing to answer.

Are you asked (or required) to return your empty cart to the building after loading the packages into your car ?

1. We are asked but don’t have to
2. We are required to return it into/close to the building
3. We are Flex drivers not Amazon workers, we leave them out in the parking lot
4. We do not have to return it, but we are asked/required to bring one inside (that someone else left) when we go in to scan our ID/pick up our full cart

Thanks !