Freezer not freezing, water in freezer. The freezer does not seem to be freezing the contents and

Question

The freezer does not seem to be freezing the contents and water is forming from the contents defrosting. Water is leaking down from the freezer to the floor. Not sure if the thermostat is working and since the manual lacks any detail, I'm not even sure where to find the thermostat or how to tell if it's broken, and how to fix. Any help would be greatly appreciated.