It's not flyable without it
Boeing insisted that pilots trained on the 737NG can fly the MAX without costly simulator time, just a short paper course.
They've insisted that before, and 47 people died when a brand-new 737-400 crashed near East Midlands Airport because the pilots only had paper conversion training from the previous version of the 737.
It appears that Boeing forgot the lessons of 8th Jan 1989 and the 737-400 when launching the 737MAX.
FFS Boeing. How many people have to die before you get it into your heads that ALL new aircraft REQUIRE simulator training? A similar model number is not enough!