How do I block ads from third-party ad networks?

Question

JavaScript

Good afternoon.
I have never worked with advertising, so I ask for help in solving a test task.
Maybe there are articles about it?
Here's how the question itself sounds:
The user loads the page of the website that hosts our script.
We do not have access to the HTML code of the page, but it is possible to agree on a specific location for this script in the HTML code.
Also on the page there are scripts of other advertising networks (the number varies), which insert ad units on the page.
The task of our script is to prevent the user from seeing ads from third-party ad networks.
You need to offer possible solutions to the problem (without implementation), and also think about the following questions (it will be good if you have your own questions):
Under what conditions is it possible to complete the task?
When does a task become completely impossible?
What do you need to know about the site and the scripts hosted on it?
Make a list of questions you would ask if you were asked to implement such a script.