What are the free services for analyzing the traffic source of competitors?

Question

Marketing

Essence of the question: there are sites of Polish competitors, you need to find out where they are advertised (banners, push notifications, etc.)
Simulyarweb either does not provide data at all, or completely superficial data.
Does anyone have a ready solution?

Answer 1

on the server there are services for sampling from similar, order it, the easiest way
is to look at ahrefs, semrush, alexa