Actually I found same case already.
Can't execute Ruby file using Powershell
But I couldn't solve it with this answer. I couldn't find where's ruby.exe. I wanted to make a comment but I don't have any reputation, so I'm asking the same question again.
The Problem is simple. When I tried to run ruby on VScode, something problem happened.
The term "ruby" is not recognized as the name of the cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1"