Issues with installing matplotlib on Windows 10 with pipwin [duplicate]

I'm trying to install matplotlib on Windows 10 (64-bit), Python version 3.9 following the instructions in this answer with pipwin. I check at Christoph Gohlke's website and the suitable version seems to be available. I installed numpy and scipy prior to this: both of them succeeded.

I don't understand why the installation fails for matplotlib.

Here's the error produced.

ERROR: Command errored out with exit status 1:
     command: 'c:\program files\python39\python.exe' -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\Ayon\\AppData\\Local\\Temp\\pip-install-lshx07yt\\kiwisolver\\setup.py'"'"'; __file__='"'"'C:\\Users\\Ayon\\AppData\\Local\\Temp\\pip-install-lshx07yt\\kiwisolver\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base 'C:\Users\Ayon\AppData\Local\Temp\pip-pip-egg-info-t2ll_1bu'
         cwd: C:\Users\Ayon\AppData\Local\Temp\pip-install-lshx07yt\kiwisolver\
    Complete output (44 lines):
    WARNING: The wheel package is not available.
      ERROR: Command errored out with exit status 1:
       command: 'c:\program files\python39\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\Ayon\\AppData\\Local\\Temp\\pip-wheel-53baidv2\\cppy\\setup.py'"'"'; __file__='"'"'C:\\Users\\Ayon\\AppData\\Local\\Temp\\pip-wheel-53baidv2\\cppy\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d 'C:\Users\Ayon\AppData\Local\Temp\pip-wheel-z0wi26qr'
           cwd: C:\Users\Ayon\AppData\Local\Temp\pip-wheel-53baidv2\cppy\
      Complete output (6 lines):
      usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
         or: setup.py --help [cmd1 cmd2 ...]
         or: setup.py --help-commands
         or: setup.py cmd --help

      error: invalid command 'bdist_wheel'
      ----------------------------------------
      ERROR: Failed building wheel for cppy
    ERROR: Failed to build one or more wheels
    Traceback (most recent call last):
      File "c:\program files\python39\lib\site-packages\setuptools\installer.py", line 128, in fetch_build_egg
        subprocess.check_call(cmd)
      File "c:\program files\python39\lib\subprocess.py", line 373, in check_call
        raise CalledProcessError(retcode, cmd)
    subprocess.CalledProcessError: Command '['c:\\program files\\python39\\python.exe', '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w', 'C:\\Users\\Ayon\\AppData\\Local\\Temp\\tmpobepce7l', '--quiet', 'cppy>=1.1.0']' returned non-zero exit status 1.