Problems with building jom and Qt5 from source on Windows

Greetings to all.

It is not possible to collect jom from isodniki. I am in the directory c:\jom\jom-build, and in the directory c:\jom\jom there is the source code itself. I do about everything according to the guide from here: https://code.qt.io/cgit/qt-labs/jom.git/tree/README. Accordingly, I set the following command to the console:

cmake c:\jom\jom -G "NMake Makefiles" -DCMAKE_PREFIX_PATH=c:\jom -DCMAKE_INSTALL_PREFIX=c:\jom\jom-install

But I get the following error message:

CMake Error at CMakeLists.txt:10 (find_package): By not providing "FindQt5.cmake" in CMAKE_MODULE_PATH this project has asked CMake to find a package configuration file provided by "Qt5", but CMake did not find one.

Could not find a package configuration file provided by "Qt5" (requested version 5.2.0) with any of the following names:

Qt5Config.cmake qt5-config.cmake

Add the installation prefix of "Qt5" to CMAKE_PREFIX_PATH or set "Qt5_DIR" to a directory containing one of the above files. If "Qt5" provides a separate development package or SDK, be sure it has been installed.

-- Configuring incomplete, errors occurred! See also "C:/jom/jom-build/CMakeFiles/CMakeOutput.log".

Where should I get Qt5Config. cmake or qt5-config.cmake and why do I need them when building a jom? I have qt5 sources, but there are no such files there. I also tried using the "Visual Studio 16 2019" generator, but the result is the same. Windows 10 operating system. And I also have a question about why this command is needed and what it does:

-DQT_QMAKE_EXECUTABLE:PATH=X:\build-jom\qt\bin\qmake.exe

I found a similar question on one of the forums, but I didn't really understand anything there.

In general, I originally wanted to build Qt5 from the source code. There, too, nothing is working out yet. We need to experiment, but the nmake utility works in 1 thread, so I wanted to install jom to deal with the installation of Qt5 itself faster.