You can’t increase your height. If you’re short, accept your height for what it is.
You can take growth hormones or some sort of steroids. But you wont get that from a doctor as long as you don't suffer from some sort of growth deficiency. People just need to accept themselves, improve their personal life by reading books and working out. I mean, it's better to fix the underlying mental insecuritiy than overcompensate your whole life subconsciously by buying big things and suffer from napoleon complex.
Sit with a straight back and stretch yourself out with stretch exercise and don't lift weights.
Most important make dua and eat food

not junk food
I tried it at the beginning of the summer holidays and mashallah I grew taller than everyone in my family than this shrinking thing started were i have to stretch out for 5 min to go to my original height nothing bad just 4-5 cm
so I continued it till Ramadan then had to stop I'm trying to start it back again so here is the update with some suggo science from Dr farax madaxweyne
-my routine i believe breathing i could be one of the most important things it makes red blood cells carry important nutrients around the body (I could be wrong red blood cells only carry oxygen i think )
-jumping Jack's at least 20 times a day
-intermittent fasting
- Getting on my knees and begging allah to give me that extra 2 inches /s
-and patience
Will update soon