Manual execution of Ruby script

How can I run a Ruby script in manually? I’d like to try out the script provided as 3/4 of the way down in Add a way for LDAP users to be created before first login, but I’m at a loss on how to do this.

I don’t think GitLab CI isn’t my answer, because the script isn’t project related.

I’d appreciate some direction to how I can go about achieving this.


[edited: moved from How To to General forum]