I have a question: “Why I don’t see ‘ignore’ button and 'difficult ’ button in the additional courses?”. But the courses created by memrise have that feature.
The community courses use an old version of our lessons whereas official courses use an updated version, especially if you’re on Early Access
The buttons are present on some of the cards, look for a triple dot menu, especially the first time you see a word
Oh you’re on iOS not android, I don’t know off the top of my head what the old lessons have in terms of difficult words and ignore, but if they are anywhere they would be on the first card you see a word, look for the triple dot menu.
Not all users have access to early access yet, but you should within a couple of weeks. Early Access is only for official courses at this time.