The chin can't be thin alone, and there is no unique way to make it thin. But my experience tells me that if the whole person loses weight, the chin will also lose weight.

The method is: control diet. If you are a boy, please ask an excellent personal trainer to make a plan for you, and the demand for protein will reach its peak after fitness. This is not eating indiscriminately, just drinking skim milk (both men and women can do it after this exercise), preferably Telunsu, because skim milk can burn fat and grow muscles after exercise, and girls try to do aerobic exercise and yoga.

My result was two months, my weight was reduced from 98 kg to 83 kg (height 186cm), and of course my chin was recovered. If you really want to lose your chin, it's best to exercise, exercise+exercise.