How can I achieve a seamless transition similar to this?

I’m trying to implement a seamless transition. As in the page seems to load in from the current page and populate. There never appears to be a load between the two. I’m assuming it’s masked by the animation itself.

When the circle is clicked on the website, it animates and fills the page.

AFAIK there’s no way to install dependencies on WF, though I’m not entirely sure. I’ve looked through the github, but I haven’t coded in quite awhile, and it was Swift. So I couldn’t make much sense of any resources.