Thanks for reaching out about your gecko and including photos. This animal is emaciated and starving for nutrients. A veterinary visit if highly recommended, ASAP, as it appears severely ill. Intestinal infections/parasite and metabolic disorders (liver, kidney) are among the most common causes. Check and correct husbandry as environmental parameters (heat, UVB exposure, humidity) are extremely important for recovery. Offer water and food through a syringe until a veterinary appointment can be made. Good luck.