What is the easiest way to replace a popular JS script with your own on most sites?

Question

JavaScript

Suppose there is some very popular script:
https://example.com/jquery-3.3.1.min.js

But this domain is blocked by ip for security or comfort reasons. However, this single script is useful, even though the rest of the server is harmful.

What is the easiest way to inject a copy of the script into the browser, so that other sites viewed will work and, as it were, would not notice anything when using this script?

Answer 1

If I understand correctly, then you can use the extension to change the link to the script like this.
https://developer.mozilla.org/en-US/docs/Mozilla/A...
Third example.

Answer 2

But this domain is blocked by ip for security or comfort reasons.

The conclusion suggests itself about the use of routing / firewall / nat, respectively, you can configure the transfer of a specific url to another, programmatically on the router / firewall / nat. Well, or locally in the browser, through the extension, but this will only work on the current device, if necessary, on all behind the firewall - the first option is more universal.

Answer 3

This is what the LocalCDN extension does.