How to provide custom Referrer-Policy header values

I want to change the referrer policy values provided by Puma and I was following this:

I did a copy and paste of the sample provided on that page into config/environments/development.rb and restarted Puma and I got this result:

Referrer policy not matching config

I saw none of those new header values in my browser. Is that file the right place to put in custom Referrer-Policy values?