How do you introduce diaper-less during bedtime? My boy is currently 3yo and has been toilet trained for 6 months.

I get my boy go toilet before sleep, beginning i still let him wear diapers during nighttime because I don't want wake him up middle of the night as a routine or wet the bed is tiring for him and can't sleep well. I observed him for 1 month he didn't wet the diapers then I slowly go without diapers.