#1: You can put your child to bed, but you cannot make him sleep.
#2: You can put your child on the potty, but you cannot make her pee or poop.
#3: You can put a tissue to your child's nose, but you cannot make him blow it.
#4: You can put good food on your child's plate, but you cannot make her eat it.
#5: You can make your child say "I'm sorry" but you cannot make him mean it.
Some things are just out of our control as parents. So don't sweat it if your child isn't doing something on this list. (S)he will eventually and probably take you by surprise when (s)he does!
It does not mean that you are a failure as a parent. Nor does it mean you should spend $150 on books full of plans for brainwashing/forcing behavior on your child.
For one thing, many, if not most, if not all, of those books by "experts" are written by people who are not parents. In fact, many aren't even people who actually care for children in any way.
Secondly, your child is one of a kind. So just because some research study got a whole bunch of other kids to adopt behavior using this "technique" doesn't mean you will get your child to do it. Besides, most of the time the kids who respond to these programs were going to adopt that behavior anyway even without the program. That's something you can't prove or disprove.
Thirdly, there is likely nothing wrong with your child. They probably just aren't "there yet". Or if their behavior is a symptom of something, that condition needs to be addressed specifically before attempting to impose plans and programs. Otherwise, you risk unnecessarily stressing yourself and your child out. If you are concerned, talk to your pediatrician about your concern. If it's just irritating you, take a deep breath and remind yourself not to sweat the small stuff. You and your child are doing JUST FINE!