Contacting customer service after making a reservation or being proactive during the reservation process are the two ways to seek wheelchair assistance with Southwest Airlines.

https://airlines-office.com/blog/southwest-airlines-wheelchair-assistance/
airlines-office.com

https://airlines-office.com/blog/southwest-airlines-wheelchair-assistance/

Get Southwest Airlines wheelchair assistance from the airport curb to/from the departure gate & any connecting point. Notify the staff at the airport.