Update WSL1 that was originally used to WSL2
MS has published the official document, there are many articles if you ask google teacher, so basically there is no problem if you follow it. There was one thing that didn't suit my environment.
If the result of> wsl --set-default-version is an invalid command, enter wsl --help. If you don't see --set-default-version, it means it's not supported by your OS and you need to update to version 1903, build 18362 or higher.
It simply says
version 1903, build 18362, but this version did not improve the above symptom, and when I updated to
version 1909, build 18363.1049,
--set-default-version was displayed.
I do not know the cause and I can not say anything because it is a verification of only one unit, but if you have the same symptom, you may try updating the build version to the latest.