1.3 separate code load on routes

Hi,
can someone point me how to load some part my webapp on certain route.
I have a react app using flow-router and for exemple I want to load another part of my code on /moderation for exemple but I don’t want that part of the code to be served on /. I look into packages to split the code but didn’t succeed to make it working.
Did someone know how to do ?
Thanks !