Only applies to user-entered or -selected URLs?

[TZeeGithub]

I am unsuccessfully trying to get Regex-Blocklist to block a URL that is accessed by a web page internally. I can get it to work for a URL I enter in the address bar, and for a URL I click on in a web page, but not for a URL that a web page loads internally. Is this use case not supported?

[AaronErhardt]

This extension uses the browser.webRequest.onBeforeRequest event to filter requests. I don't know what you mean with internal requests, but it might be the case that the browser does not pass that information to the extension.

[TZeeGithub]

I don't know what you mean with internal requests

Sorry for being unclear. I am referring to when a web page's HTML, or more often JavaScript, accesses / loads another URL, e.g. for a resource such as an image.