Big todd.... PIN codes are activated in the settings. Roku has their own PIN settings and UltraFlix does as well. If you go into settings you can turn it on or off. This is set up and used for people to prevent kids from buying movies. I would try turning it off on your Roku and let us know what the result is.
I'm using Roku as well on one of my 4K TV's and of course as already discussed here I get the receipt on my email account from UltraFlix thanking me for my rental.