when you fly with Southwest many times, Southwest gives a coupon that you can use in future travel, which means if you want to travel in the future. You can use the coupon at the time of the booking. Your southwest ticket is some less expensive.
You can use your coupon by visiting the website www.southwest.com, and you can book a ticket. Then, you can use your Luv voucher, so if you face any problem, call the southwest customer service number 1-800-I-FLY-SWA (1-800-435-9792) or dial +1 801 630 835 8 and get the information!
I hope the information given above will be helpful to you.!