My 3yo daughter goes toilet on her own to pee now but she is very nervous/afraid of pooping at the toilet. How can I encourage her? We've tried encouragement, threats and diaper free, but she just won't dare to go near toilet when she wants to poop.

Did I ask what's her fear in using the toilet to poo? Dont think is coz she is afraid of falling in the toilet bowl as she is already using that to urinate. Show her pic of children's backside with bad nappy rash to tell her that it is dirty to poo in diapers. Otherwise slowly talk to her using dolls and get the answer out from there.