@leocg On Firefox it seems very simple. If I have no exceptions on "about:config dom.popup_allowed_events", when I go to https://www.duolingo.com/ and click "Sign in with Google", the window "https://accounts.google.com/signin/..." is blocked. Chrome and Opera let it open.
Posts made by shffx
RE: How can I block all pop-ups without addons?Opera for Windows