The fat that your body burns when you're losing weight leaves your body through your sweat so the fat goes through a metabolism process that is very complicated which then gets turned into sweat.
Then as you sweat the body fat comes out of your skin.
The body fat also leaves your body through your urine and through your lungs when you breathe out.
So it's a very complicated process that the body fat goes through in your body to allow the body fat to exit your body but it does so in very different ways.
You can have weight loss surgery which has the surgeon remove excess body fat surgically but it can cost quite a bit of money for the weight loss surgery.
But with weight loss surgery you lose a lot of weight immediately so it can be worth it if you can afford to have weight loss surgery.