How to make remote access (ala teamviewer) to a certain program/window?

Question

Remote access

Hello.
You need to do the following, provide remote access to a user on the X computer to a window or program (for example, Opera) on the YGREK computer. Access and visibility of the window must be maintained even if the user on the YGREK computer minimizes the window.
Thank you.

Answer 1

https://ru.wikipedia.org/wiki/%D0%A2%D0%B5%D1%80%D...

Answer 2

WebRTC