Okay, I've just done this for the third time (third child, not 3 attempts, lol!), so I shall witter on and then leave all baby and toddler-related threads forever.
There are several takes on this:
(1) if nappies are dry in the morning, that's a good sign (obviously). Leave off and see what happens.
(2) nappies may be wet in the morning because child is actually dry at night but is having an enormous wee first thing in the morning. Leaky nappies at 6am and/or puddles on bathroom floor may be signs of this. Again, worth trying to leave off nappies and see what happens, but make sure potty is handy, ie. right by the bed with a couple of old towels underneath. IME most nighttime accidents happen as the child is trying to get to the loo for that first wee of the day.
(3) Child may not be ready at all and may be incapable of holding on all night, in which case there's no point trying to force it. I've not had one of these myself, but clearly there's a lot of them about, so no point getting knotted up about it. Likely to be hereditary, so find out what age dh was dry at night!
(4) Getting them up at night is meant to be counterproductive, apparently. If they really can't go through the night, then they can't go through, so back to (3). Ditto restricting fluids in the evening, though clearly letting them drink huge quantities just before bedtime is not the best plan.