How to make a back-end for browser extensions?

Question

Python

I want to make an extension for chrome that will receive and send data to the site. Any programming language, whether it be java or python, located on the local machine can make requests to a remote server. Since I only see on the Internet how to create a manifest.json, popup.html, icon.png, popup.js file, the question arises in what language can I make a back-end and in general how to make this back-end, or maybe you need to create a plug-in in this case?

Answer 1

Chrome extensions are written entirely in JavaScript. Accordingly, if you want to process data from the site on your PC exactly inside the extension, then the algorithm will be as follows:
1. Inside the background page or pop-up window, make a regular AJAX request to your site
2. Parse this received through AJAX and process it as you like 3.
Send the results of the calculation back to the server through the same AJAX

Answer 2

In this context, you can consider the plugin as a regular web application that goes to the server using some kind of api