I will bet my chrome grill the seat cable cable is broken.
Cables on both my seats were broken when I bought my Jeep.
Here's a write-up that helped me when I was fixing mine
Jeep Wrangler Seat Track Release Cable Repair
You can get new cables here, but make sure you get the right one, there's at least 4 different types over the years.
I got the wrong cables for mine, but was lucky to be able to modify them to get them to work - you will need to pull your seat to see which one you need.
Jeeps Are Us | OEM Jeep Parts and Accessories
Some cleverer folks have made their own cables.
In the meantime you can do what Mark1kim suggests and use the paddle under the seat.
It's not very convenient to use (that's why we have the cables) and be careful with your fingers - there's lot's of moving parts under the seat