Disney-operated resort hotels at WDW do not have rental car counters or rental car return.
The WDW Dolphin and several non-Disney-operated Downtown Disney area hotels have rental companies. Also, various hotels that are just off property have them. And there are dedicated rental car facilities, such as Hertz on Highway 192, not far from Disney's Animal Kingdom.
You can make reservations to return your rental car at one of these many places. Of course, where depends on which rental car company you want to use. Most, but not all, of these places will pick you up at, and drive you back to, your Disney resort.