UnicodeEncodeError when building ESP-IDF project

Question

I want to repeat the sip-call project, but I just can't assemble the project without errors. Apparently, the files that are in it are not enough to build the project. I have already tried many methods and can't get any success. What am I doing:

I'm cloning the sip-call repository to my computer. I do idf.py build. The message appears:

CMakeLists.txt not found in project directory D:\sip-call

Then I add the file CMakeLists.txt to the sip-call folder. The file contains the text:

cmake_minimum_required(VERSION 3.16)

include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(sip-call)

And I do idf.py build. The project is compiled, a lot of text is output to the console, and eventually the compilation ends with an error:

FAILED: sip-call.elf
...
undefined reference to 'app_main'

I add the file CMakeLists.txt to the main folder. The file contains the text:

idf_component_register(SRCS "main.c"
                     INCLUDE_DIRS "")

And I do idf.py build. I get the error:

  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Program Files\Python39\Lib\site-packages\kconfgen\__main__.py", line 16, in <module>
    main()
  File "C:\Program Files\Python39\Lib\site-packages\kconfgen\core.py", line 402, in main
    output_function(deprecated_options, config, temp_file)
  File "C:\Program Files\Python39\Lib\site-packages\kconfgen\core.py", line 566, in write_cmake
    write_node(n)
  File "C:\Program Files\Python39\Lib\site-packages\kconfgen\core.py", line 557, in write_node
    write('set({}{} "{}")\n'.format(prefix, sym.name, val))
  File "encodings\cp1251.py", line 19, in encode
UnicodeEncodeError: 'charmap' codec can't encode character '\xfc' in position 36: character maps to <undefined>

If I add library dependencies in the CMakeLists.txt file in the main folder, as was done in the original project by chrta in his original sip-call project:

idf_component_register(SRCS ./main.cpp
                    REQUIRES
                    driver
                    esp_netif
                    esp_wifi
                    mbedtls
                    nvs_flash
                    sip_client
                    audio_client
                    display
                    #web_server

                    INCLUDE_DIRS "")

target_compile_options(${COMPONENT_LIB} PRIVATE -std=gnu++17)

and do idf.py build, the compiler will display a message about unfamiliar libraries with a hint:

HINT: The component sip_client could not be found.

Then I add a CMakeLists.txt file to each local library. The file contains the text:

idf_component_register(INCLUDE_DIRS include)

And again I get the same error:

File "encodings\cp1251.py", line 19, in encode
UnicodeEncodeError: 'charmap' codec can't encode character '\xfc' in position 36: character maps to <undefined>

I use Windows 10, ESP-IDF v5.2.1

Any other projects from the esp-idf examples are built without errors.

Please tell me how to build the sip-call project without errors? What files are needed for this and what content should they contain? Thank you