Create a chrome extension for a web browser

I want to create a Chrome extension so that my web browser becomes the default browser for anyone who adds the Chrome extension. Just like Ecosia does "Add to Chrome - It´s free" (See attached image or directly on https://www.ecosia.org/). My web browser is live at https://konlap.com
My web browser is built on top of React js and Tailwind css. If you consider important, please explain in general lines how you will get the task done.