Pass Data From JS to HTML

Hello,

I’m new to developing for Atlassian products (and web in general), and I’ve been reading through the documentation and forum for the past couple days and have been having trouble understanding some concepts. I was hoping someone here couple explain some concepts to me as a jumping off point for me.

I’m making a simple video player macro app for Confluence Cloud with a Forge Custom UI app. I’ve been able to make an app that plays a publicly hosted .mp4 file in the static index.html, but the goal is for users to enter a URL in a UI Kit MacroConfig during page edit, and for that string to be passed to the html for the video player to play it.

How would I go about creating that, or are there any code examples that I can look at that pass values to html?