I need to make a chrome extension that checks the requested URL (before page load) and displays a full screen blocker page if the URL is in a given list of blocked URLs.

How can I achieve such a fullscreen page during page load? Do I need to inject HTML elements into the loaded page and basically cover the page with the content I'd like to show or is it somehow possible to load a complete HTML page before actually accessing the requested URL?

This is how it should work:

User enters URL -> Extension checks if URL is blocked -> if yes, show blocker page / if not load page normally