Metahuman iOS

When I launch to iOS with cooking on the fly, the metahuman doesn’t load the face’s material and the whole thing freezes. What settings do I have to change to make it run on a mobile device?

I suspect that just drag and dropping a metahuman in to the game as is wont work for mobile, what do I have to do to optimise it?
I’ve tried with both the 8k version and the 2k version but its exactly the same no speed increase, freezing is the same, same materials load before it freezes. What am I doing wrong?