Another way is to hang your feet and legs upside down on the wall before going to bed every day, so that your body and legs are at 90 degrees and your ass is close to the wall. Stick to 15 minutes every day. You can also put a pillow on the mat when you sleep at night, which can help you grow taller and stovepipe.
In short, exercise every day and don't sit in a chair for a long time. I hope my answer will satisfy you! (This answer is personal, please don't copy it. )