This links to “Firefox Focus” which is different in the iOS App Store than “Firefox”. I had no idea.
This Firefox Focus on iOS does effectively block adds on a recipe site unlike plain Firefox. I just did a cursory head to head test on the same recipe site url.
I use it on iOS daily and there’s no ad blocker. The page you linked only mentions tracking blocking. If you actually have ad blocking enabled, I’m sure a lot of us would love to hear how you did it.