My son will turn 3 years old and he want to poop only in diapers

A. No but you don’t have to use diapers completely stop using diapers and make your child sit on the commode every two or three hours as per your comfort and comfortably you have to make your child understand that you’re holding the child child is going to fall so slowly the child will be trained will learn to adapt and cooperative stop giving diapers then only things will work you have to be little strict over here to teach her child