How to Fixed UI and Animation On Scroll Down

Design help Layout & Design
1

I’m really trying to make this work but I can’t seem to find an answer.
I’m trying to animate a Lottie while scrolling down but the whole page must be wrapped like in this picture:

Webflow_Community_PRIME
Webflow_Community_PRIME1440×1080 131 KB

In my Read-Only you can find two pages. The first one works great, but it doesnt have the fixed wrapper like what I need. The second page is my failed attempt to make it work.

Read Only:
http://preview.webflow.com/preview/prime-9bab64?utm_medium=preview_link&utm_source=dashboard&utm_content=prime-9bab64&preview=60262a5ee75e262ca623a56d39b72935&workflow=preview

Is there a way to have this UI wrapper (100vh) and still making the lottie on scroll animation work? Is there a work around? I tried one in the third page but can’t make it work (Like a fixed something above it all?)

Thanks in advance!