You can rent them near the resort bus stops and also they have them next to the entrance to the lime garage.
Those are the two I've seen
In mde go to tge guest services tab on Disney springs and you can see the exact location
There’s a small rental location near the Lime Garage. As soon as you exit the escalator or elevator, you’ll see the wheelchairs on the left side. There may also be a location for the Orange Garage.
This is from the disneysprings.com site:
Designated parking spaces for Guests with disabilities are available in both the Orange and Lime Garages. A valid disability parking permit is required. Wheelchair, ECV and stroller rentals are available at the nearby Sundries location next to the Town Center bus loop.