S.H.
Its too young to expect him to have FULL control at night.
Night-time control and dryness does not occur until between 5-7 years old.
My daughter, still used night time diapers until 5 years old.
AND, we use water-proof bed pads under her, just in case she has accidents.
A child WILL have accidents. GUARANTEED.
If you wake him to go to the toilet in the middle of the night, it is disconcerting... and they will not get a good sleep. Boys also train later, than girls.
Daytime and night-time 'control' and training are 2 DIFFERENT things. Night-time control takes longer.
Being that it is just a developmental and biological/physiological origin.... motivators/punishments won't work. It just frustrates the child... or humiliates them because they cannot be 'perfect' about it, yet. Please, do not expect 'perfection' about this. MANY MANY MANY kids, still use a diaper at night... even Kindergarteners. Because they are not at the age where it is fully mastered yet.
He is still too young, for this 'perfection' and mastery. It is all about the physiological and emotional and just plain developmental age appropriate functions.
Night time 'dryness' cannot be 'won'.... it cannot be created or forced by rewards/punishments. It is either the child can or cannot hold it.
ALSO, my daughter at her age, still has pee accidents at night sometimes, because she just sleeps SO SO soundly. AND she even told us once that she had a dream that she WAS on the toilet... and then she felt herself get wet. But NO big deal... we have a waterproof bed pad under her. No fret. I just get up, put a new pad under her, she changes pajamas, and back to bed. No punishment, no scolding, no nothing. It's not worth it. She couldn't help it. It's not her fault... she doesn't do it on purpose, she doesn't do it to irk me, she isn't doing it to be 'naughty', she isn't even fully aware that she had an accident until its too late. But sometimes, she will get up to go pee. Not usually. But she can be dry the whole night. It varies EACH night. Each night is different. But it's all based on age and maturity and biological development...which cannot be rushed, before it's time.
All the best,
Susan