how can i build web application like webdev(like google lighthouse) in react+nodejs need ideas

Hello there I am trying to build an application like a (Web.dev)[https://web.dev/measure/] in reactjs but I don't have any idea about that like how can I build it which tools and things I have to use I know things related to UI like I can use etc material UI or any other library but I am having big doubt on how to run tests on the sites like after putting/pasting our site URL in that input box how can I run the tests on the whole site and then generating a report
and also i know one thing is react will help me for building UI components but for backend things testing task lies outside the domain of client JS so for that i know we to use nodejs but can anyone guide for this how can i build this
if anyone has ideas about this then please answer below have a good day all.