How to Install VMTK in 3d Slicer?

I need to install vmtk(to use vmtkcenterlinesmoothing, etc)in 3d slicer through the python interactor. How do I do that, I am on a windows terminal, any help is appreciated.
I know I can install scipy and others using slicer.utils.pip_install(), but that does not work for vmtk. Can I use conda? please let me, thanks.
Operating system: windows 10
Slicer version:4.11

https://www.slicer.org/wiki/Documentation/Nightly/ScriptRepository#Download_and_install_extension