My child is scared of clogging the toilet and keeps pooping on the floor.
In your child’s presence, take the stools off the floor and flush it down the toilet so that the child can see that it will not clog and that it is its purpose.
Please discuss this with the pediatrician
See a GI specialist.
See this link...
https://theraplay4kids.com/new-blog-35
and
https://www.healthychildren.org/English/ages-stages/toddler/toilet-training/Pages/Emotional-Issues-and-Bathroom-Problems.aspx