Anyone familiar with progress bar "scroll indicator"

Good Day Everyone,

I have been looking at the w3bschools tutorial on Scroll Indicators for guidance. ""

Where I am stuck is on how to insert HTML code to create the animation. If this is a silly way to do it or incorrect, Id like to know. Sorry if this an annoying question, I'm a noob.

Hello I created and uploaded the component as Scroll Indicator, simply add the component to your design and dissect it