The correct method of abdominal breathing

I think the correct method of abdominal breathing is as follows:

Take the posture of standing, sitting and lying down, relax, inhale through the nose, tuck in the abdomen, and exhale slowly after 10- 15 seconds, breathing 4 times per minute, which can be combined with chest breathing. Practice for 5- 15 minutes each time, 1-2 times a day, especially with slight heat and slight sweat.