JavaScript communicating with a C# program?

Question

JavaScript

Hello, I ran into a problem: a banner is written in JS, which is embedded in the page and fixed in a given position. According to the assignment, I need to read statistics, this is done by a desktop application written using .Net (WPF) tools.
It seems nothing complicated, but I've already been sitting for an hour and I can't figure out how to properly establish a connection between them.
As far as I know, in theory, I need my application to be an http server so that JS can send a request with data to it. How correct is this or are there other ways to do it much easier?
Thanks a lot for your answers.