Thanks Seadog! I emailed the factory and their response from their help desk was no help. They said they checked with their warranty rep and they said above the slide. Well that’s obvious, lol. Then said to check with a certified forest river dealer.
With that said, I did get the topper installed this weekend. Here is a pic. I went to the top of the gutter. I probably could have lowered it a bit but the pre-installed brackets on the slide from the factory were at the bottom of the trim. I ended up with a little slope.