1. Enable Windows Hypervisor Platform
If you didn't enable this feature, you may see "No action was taken as a system reboot is required." message when you install WSL.
2. Install WSL with Administrative Powershell
wsl --install --d debian
2.1 Checking list of WSL distro
wsl --list --online
3. Create account for distro plaform. New windows may show "Installing, this may take a few minutes..." awhile, just type Enter. So you can create new UNIX account.