Please document in README where

[yurivict]

Python binding's build fails:

Make Error at CMakeLists.txt:36 (find_package):
  By not providing "FindPythonExtensions.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "PythonExtensions", but CMake did not find one.

  Could not find a package configuration file provided by "PythonExtensions"
  with any of the following names:

    PythonExtensionsConfig.cmake
    pythonextensions-config.cmake

  Add the installation prefix of "PythonExtensions" to CMAKE_PREFIX_PATH or
  set "PythonExtensions_DIR" to a directory containing one of the above
  files.  If "PythonExtensions" provides a separate development package or
  SDK, be sure it has been installed.

skbuild doesn't install such files.
The closest files that it installs are

/usr/local/lib/python3.9/site-packages/skbuild/resources/cmake/FindPythonExtensions.cmake
/usr/local/lib/python3.9/site-packages/skbuild/resources/cmake/UsePythonExtensions.cmake

Could you please document in the README where PythonExtensionsConfig.cmake is supposed to come from?