FWIW, got this:

  CMake Error at /opt/homebrew/Cellar/cmake/3.22.2/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find Soup (missing: Soup_LIBRARY)
  Call Stack (most recent call first):
  /opt/homebrew/Cellar/cmake/3.22.2/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:594 (_FPHSA_FAILURE_MESSAGE)
  cmake/FindSoup.cmake:29 (find_package_handle_standard_args)
  cmake/MultiFind.cmake:20 (find_package)
  plugins/http-files/CMakeLists.txt:1 (find_packages)

trying to follow the instructions you pointed to. Gotta learn CMake some day...