According to step 5, the auth database is single quoted as '$external'.

The quotes are not required for the Windows cmd.exe shell, which is the default shell.

However the quotes can be used when using the Windows PowerShell, which is not the default shell.

I would suggest updating the docs to remove the single quote and add caveats the this syntax is specific to the cmd shell.

Optionally add the PowerShell syntax and caveats.