How to determine the source of landing page generation?

Question

JavaScript

There is a site
In the source code there is a link to the JS files static.best-gooods.ru/js/****.js
I see a similar domain in so many sites, but I can’t understand the essence of the origin. This is a constructor, CPA network or something else. This is necessary in order to understand the structure of the site in terms of sending data from forms and understand where it all goes.
The design like best-goods.ru/(site name)"> I want to point out right away
that despite the similarity of subdomains or subfolders, the sites do not belong to the same owner. At the same time, when opening domains, there is no content on them.

Answer 1

Here are a couple more landing page examples. We look at the address
land-gooods.ru/kylieedition
land-gooods.ru/fishxxl
reals-gooods.ru/gps2/?ref=3906&lnk=1023264
The /static.best-gooods.ru construction also appears in the source codes

Answer 2

I was offered a job several times, which consists in parsing landing pages with some special software and their symbolic alteration - logo, colors ... I'm not interested, so I didn't specify the details, but perhaps they are.

Answer 3

These are landing pages of one of the CPA networks