You can use the Firefox Focus browser in iOS, which has ad blocking built in, but can't use it as an adblocker for the main Firefox browser. I suspect that's d

You can use the Firefox Focus browser in iOS, which has ad blocking built in, but can't use it as an adblocker for the main Firefox browser. I suspect that's due to the app sandboxing - there's no way for Focus (as a standalone app) to intercept and modify requests for Firefox (another standalone app). Mozilla could ship a copy of regular Firefox with the Focus features built in, but seem to want people to just use the Firefox Focus Browser instead (though that lacks the full feature set of Firefox).