I don't have that model but check around near it for a hidden nut under the carpet or in a hidden nook somewhere close. On mine the nut was the same size as the wheel nuts so you could use the jack handle to drop/raise the tire.
You had to peel up the carpet and take out a small wood cover on a hole in the floor near the center of the wheel inside.
2017 SLX 195RB
2021 Jeep Grand Cherokee Summit L 5.7L V8
Andersen WDH hitch, Renogy 100 AH Lithium &
200 Watts solar panels from Renogy
Prev. '14 Jeep Grand Cherokee Overland, gas 3.6 V6