First, Welcome to the Keystone RV Forum. Many RV systems are similar, some even identical and most appliances, tanks, components are used across all brands, regardless of manufacturer.
The 2020 puma 32bhis is a Forest River RV, not a Keystone RV product. This forum doesn't cater to owners of Forest River products, although many members either have owned RV's manufactured by Forest River or are familiar with them. You might want to search for a Forest River owner's forum.
As for the owner's manual for your trailer, the Forest River/Puma website does have an Owner's link and there are "interactive Owner's Manuals" available for you to view/download. Here is a link to that section of the Palamino website:
https://palominorv.com/owners#manuals
Good Luck with your new to you trailer.