Dog.rb not loading

I’m confused about where we should be entering the code for files like dog.rb and primes.rb etc…

Thi is in Debugging/Bug Hunting

I tried entering it into a file called dog.rb and then loading it in pry but I get the following:
NameError: undefined local variable or method `dog’ for main:Object

from (pry):1:in `pry

I feel like every time there is some new lesson on using the terminal, the instructions are very unclear about how to proceed or terms are used that are undefined. Am I supposed to be in a particular file or directory?

Figured it out.
Quotes needed.