When I search, it says it is available on Hoopla for free, meaning you have to have that channel/app on your device to view. It all depends on the apps you have on your device and what channels you have available to you (free or subscribed). It works pretty similar to what a cable subscription works like, if you don't have the channel (free or otherwise) you can't see the program. Roku doesn't control the content on third party channels like Hoopla, so your mileage may vary in terms of what they have currently available and if they offer it free or not.
There are several different titles with that name, but I presume you mean the newest one and it doesn't show up in Hoopla as a currently available title. It may have had limited time availability for the holiday and been removed.