I need to install an app on a newer fire stick

I have an app in my Apps Library that I would like to download but it dosen't appear in the library for this model (Fire TV Stick 4K Max 2nd Gen) I know for sure this works on the Fire Stick 4K 1st gen but not any newer models, when I select "Deliver to" on the apps library on the Amazon website it isn't compatible, this has happened before on fire tablets as well, some models can't get older apps for whatever reason. Is there a method to get the apps? The app I'm trying to get is removed from the Amazon Appstore but only appears in the library for older models.