3 yo and pooping in diaper still

[Crayola kiddies]

Well if you know when he needs to go as he is waiting at the bedroom door then put him on the potty and tell him to go poop then he gets to go to bed ..... I have a potty at the edge of my kitchen area which is right beside the bathroom and I am able to watch the child on the potty and the rest if the children in the playroom. Put him on and tell him to stay there .... If he has a melt down so be it stay strong.