Animated Folds
You might want to try the InDesign Publish Online capability if that's available as part of your current subscription. Check out https://adobe.ly/2yTI8OE and look at the Los Angeles example
Below I give a few eaxample of trifold leaflet online products - so far all cost (quite a lot!!) to do anything nicely. What you see here are the freebee overings (though I haven't tried to tweak them for size etc).
https://simplebooklet.com/login.php:
https://www.flipsnack.com/:
https://flippingbook.com/
This site doesn't seem to do trifolds
https://fliphtml5.com/
This site also doesn't seem to do trifolds and, as you can see, it embeds adverts unless you upgarde (min £12 per month, which seems about standard
https://issuu.com/
ISSUU doesn't allow embedded flipbooks unless you upgrade (£16 per month) but you can open a new webpage on a new tab - It's not very nice but you can create as many books as you want. I don't think there is a trifold option.
ISSUU Test Pagehttps://online.visual-paradigm.com
An embedded InDesign
Another embedded InDesign
Flowpage created HTML5 with pager turn