To get your son to actually pee in the potty, get into and establish a routine.
For example you could start having your son sit on the toilet or potty after waking with a dry diaper, or within 45 minutes to an hour after they drink something.
You should only place your son on the potty for a couple of minutes a couple of times a day and let him get up if he wants to.
While your son is on the potty you could try turning on the water or having your son place their hands into a warm bowl of water while sitting which can sometimes trigger the release of pee.
If your son is wearing diapers you should place them in underwear and set a timer so that you know when he is about to pee and a few minutes before he usually pees, you can take him to the potty.
If he has accidents don't make him ashamed of them but just state that it's okay and he will get it next time.
Having your son in underwear instead of pull ups or a diaper can help him feel wet and help him decide to use the toilet instead of his pants.
Potty training can take a few days or longer so don't give up if he's still not getting it as he will eventually get the hang of the potty.
Things you should not do while potty training are punish for any accidents, pressure the child or force the child to sit on the toilet for extended periods of time.
It's also important that when potty training that you don't begin the potty training too early, before the child shows any readiness signs and it's also important that you don't compare your child to others who may have potty trained earlier.
You should wait until your child shows signs of readiness to potty train such as showing interest in using the toilet, staying dry for longer periods or even being able to pull down loose clothing.
Potty training your child should be a positive experience without any battle of wills and without the child being pressured or forced.
You should also never punish your child for accidents as accidents are a very normal part of the potty training process and punishing your child for having accidents during potty training can create anxiety in the child and make the child less likely to try again.
You should also keep the potty breaks short and positive and don't force the child to sit until they go and don't ask them do you want to go to the toilet as doing so can actually result in a no response and instead you should offer a choice or suggest a potty break.
You should also never shame your child or use any negative language and always stay positive and encouraging, even when the child has accidents.
Also avoid stopping and starting of the potty training frequently as consistency is key in potty training and so you should try to avoid confusing your child with inconsistent potty training methods.
Also never flush the toilet while the child is on it as it can be startling and avoid getting angry or frustrated as it can make the potty training take longer.