How do I get show-doc to work with pry for Ruby?

Question

I installed pry and pry-doc on Ubunutu WSL for Windows 10. When I try to use show-doc on pry to get information about a method it doesn't work. Picture of the error I get

Here is the code:

[1] pry(main)> require 'pry-doc'
=> true
[2] pry(main)> show-doc String#end_with?
Error: Cannot locate this method: end_with?. (source_location returns nil)