Eidter;notepad.exe

Linux; LilyPond 2.26.0-linux-x86_64.tar.gz--- install to WSL(Linux=Ubuntu)
         Windows OS download-file is Usually the file is stored here (C:\Users\?????\Downloads\........)
Do download   lilypond-2.26.0-linux-x86_64.tar.gz
         Downloaded file   C:\Users\?????\Downloads\lilypond-2.26.0-linux-x86_64.tar.gz
                                                        ===================================

Windows OS
Like this;     ( yukio=????? )

         !! Please avoid moving this lilypond-2.26.0-linux-x86_64.tar.gz to the Ubnutu environment using explorer.exe (though you can actually do that). !!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

WSL(Linux=Ubuntu)
   (The following explanation is based on my PC environment.) Please interpret it based on your own screen display.(?????@****:)

1); Check "PATH"

   $ echo $PATH[Enter]
/home/?????/bin    <=== Check whether "bin" exists(And at the beginning of the top line).
However, when you install Linux, even though there is /home/?????,
                 there should not be /home/?????/bin
Create a bin.
       ?????@****:~$ mkdir bin[Enter]
---- Once you have done this, close (exit) WSL (Ubuntu) and then start WSL (Ubuntu) again. ----
Then,
WSL (ubuntu) will automatically recognize this bin, and the PATH value will be
/home/?????/bin:/user/local/...... as shown in the left image.

2); Move and DO! "lilypond-2.26.0-linux-x86_64.tar.gz" to the Linux side(from, C:\Users\?????\Downloads\....).
                                                                                                                       ==========================

    ?????@****:~$ mv /mnt/c/Users/?????/Downloads/*.gz ./[Enter] And then, DO! ?????@****:~$ tar xvfz lilypond-2.26.0-linux-x86_64.tar.gz[Enter]
(See below ........ "bin" is there and "lilypond-2.26.0" has been created.)

<=== Already created. "bin"
<=== created. "lilypond-2.26.0"

<=== File moved here.

Runtime configuration for lilypond-2.26.0
Contents of "lilypond-2.26.0".
?????@****:~$ ls -lX lilypond-2.26.0[Enter]         Contents of the "lilypond-2.26.0/bin".
?????@****:~$ ls -lX lilypond-2.26.0/bin[Enter]
There is nothing in bin (files).

you will create a symbolic link within this "bin" directory.

)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/abc2ly ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/convert-ly ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/etf2ly ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/lilymidi ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/lilypond ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/lilypond-book ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/lilypond-invoke-editor ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/midi2ly ./[Enter]
)   ?????@****:~/bin$ ln -s ../lilypond-2.26.0/bin/musicxml2ly ./[Enter]
Well, then ! Like this

  ?????@****:~$ cd ../[Enter]

                 This completes the "lilypond version 2.26.0" installation process.