You wouldn’t necessarily gain height with improving posture with anterior pelvic tilt.

By improving APT, where you gain height at the hip, you will shrink at the shoulder and upper back by widening the stature and crunching forward.

If you want to be taller; tuck you tail, shoulder back half way, get your head over your torso and tuck your chin just a little. The top of your head is flat, and if you tuck your chin down just a bit if will lift the back of your head a little bit higher.