What engine is the site based on?

Question

CMS

Tell me, on what engine is the site implemented?
We plan to make a version of the site for Europe with support for paypal payment systems, card billing and courier services in Europe.
https://www.optix.su/

Answer 1

1. Enter a request
in Yandex or Google 2. Open one or more links
3. Enter the address of the desired site ( https://www.optix.su/ ) and click Detect (Find, Determine).
4. We get one or more options or the option that the CMS is self-written.
A description of the server, installed OS, IP address, and so on will also be available.
In this case, CMS is not defined.
So the only option left is that there is a self-written note.

Answer 2

We plan to make a version of the site for Europe with support for paypal payment systems, card billing and courier services in Europe.

The choice of engine is based on such requirements - as the choice of paint color for trips out of town.
In short, it can be done on any engine.

Answer 3

If they (the owners of https://www.optix.su/) order you to make a version of their site for Europe, you have every right to ask to be provided with all the technical information.
You can be motivated by the fact that then you can make it cheaper than developing from 0.
If you just want to make a "similar site", but no matter what CMS. Take the one with which you know how to work.