1. Add this Header custom code

<link rel="stylesheet" type="text/css" href="https://unpkg.com/fullpage.js/dist/fullpage.min.css" />

Either in the site's Settings Custom Code tab, or in a page's Settings panel in the custom code section.

2. Add this Footer custom code

<script type="text/javascript" src="https://unpkg.com/fullpage.js/dist/fullpage.min.js"></script>

<script>
// fullpage.js initialization  
new fullpage('#fullpage', {
scrollingSpeed: 1000,
verticalCentered: false
});
</script>

Either in the site's Settings Custom Code tab, or in a page's Settings panel in the custom code section.

3. Create this structure of divs in Webflow

The fullpage div must have an ID named fullpage. Set it in the Settings tab.

The section divs must have a class named section. Set it in the Style tab.

4. Style the sections

(And add some content to each of them.)

Publish and test.

This is the most simple demo to make sure you're achieving the right structure in Webflow, and that the fullpage.js library works on your page.

Fullpage.js is complex and there's a lot of documention for you to read to implement it the right way. For instance, this demo kind of breaks Safari mobile bottom bar behavior, it's also not suitable to work with Webflow IX as is.

It also doesn't take into account situations where the sections are higher than 100vh, nor side scrolling slides and a lot of other aspect that fullpage.js handles very well when you set it up the right way.