Using 11-36t 9 speed derailleur with 11-40t 9 speed cassette

So I’ve got the shimano altus rd-m2000 and it says that it only supports 11-36t. However, I’ve seen people on forums say that it’s possible with this derailleur. Even it I was wondering if with a derailleur extender I’d be able to run a larger range, such as 11-40 or 11-42?