Toilet Training - Poo issue!!

My three year old refuses to do poo in the toilet! He is fine with wee (although he does need to be reminded occasionally and almost always gets there slighty too late leaving a residue in his pants!) but absolutely REFUSES to do poo in the toilet. He does a poo every night at around the same time, in his nappy (which he still wears at night) after we have put him to bed. He has even done it while we are standing there talking to him about how he has to do his poo in the toilet. I fear it is becoming a real emotional issue with him and don't know how to resolve this! Any suggestions https://100001.onl/ https://1921681254.mx/???