You can't right now. There are no Qt wrappers for Nim as Qt has done some funky
stuff with their C code, and c2nim isn't quite good enough at interpreting C
headers to tackle Qt. If you want to attempt it I and I assume other people
would be very grateful. If no Qt isn't a showstopper for you, then you could
try the `official gtk2 wrapper <https://github.com/nim-lang/gtk2>`_ or `this
unofficial gtk3 wrapper <https://github.com/StefanSalewski/nim-gtk3>`_. I would
also highly recommend `nimx <https://github.com/yglukhov/nimx>`_ a
cross-platform GUI framework in Nim. It wouldn't be the same as developing in
something like gtk2, 3 or Qt but for nim gui development, it's hard to beat.