Build Slicer with IGT

Development
1

I am building Slicer with SlicerIGT.
I want the IGT module to be automatically added in Slicer when the Slicer.exe is created.

Where should I put the following commands in the top CMakeLists.txt of the Slicer code? Is it OK to put the commands at the end?

#-----------------------------------------------------------------------------
# SlicerIGT
set(extension_name "SlicerIGT")
set(${extension_name}_SOURCE_DIR "${CMAKE_BINARY_DIR}/${extension_name}")
FetchContent_Populate(${extension_name}
  SOURCE_DIR ${${extension_name}_SOURCE_DIR}
  GIT_REPOSITORY ${EP_GIT_PROTOCOL}://github.com/slicerigt/slicerigt.git
  GIT_TAG master
  GIT_PROGRESS 1
  QUIET
  )
list(APPEND Slicer_EXTENSION_SOURCE_DIRS ${${extension_name}_SOURCE_DIR})

Further, is there any example of using Slicer_EXTENSION_SOURCE_DIRS in cmakelist.txt instead of using the above commands?

Thank you