Well, we make sure not to give them too many liquids before bed, and we make sure they sit down on the toilet for 10 seconds before bed even if they protest.

3y.o: ‘I don’t have to go!’ me: ‘sit down’ 3y.o: ‘noooooo’ me: ‘sit’ 3y.o: ‘ohhh....’

This is the same throughout the day, you don’t listen to them, you just make them sit down at regular intervals esp. if going out somewhere.