Web application How to connect and write it?

Question

Node.js

Good afternoon!
Completely confused about how to write this.
You need to make an application that can be connected to the site and monitor it:
create a click map, track the number of users, IPs, in short, collect data for analysis
Collect everything in a database
And the question is how to write it in a stack: JavaScript, Node.JS, React, MySQL
I don’t understand how to connect it together
And how it will connect to the site as a result of this whole thing in order to collect such data from it
Tell me plz // point me in the right direction, I’m confused

Answer 1

you add REST API with http authorization to the site. the application sends requests to the site and interprets the results.