You can potty train at night using overnight diapers or training pants. There's no one right answer!
One benefit to overnight diapers is that they tend to have more absorptive materials and won't leave you with wet sheets to clean in the morning (or middle of the night...). On the other hand, training pants do not typically hold as much liquid, which means a child will feel more wetness and it might cause them to wake when they have an accident. This knowledge of when they're peeing can be useful for you and also build body awareness for them.