When I use Krita and I try to play the animation, it crashes and when I use Krita for a couple of minutes it also crashes

Well, there's obviously something wrong there, but it's not necessarily a bug in krita. We can try to find out more, but you need to give some information.

* What version of macOS do you use?
* Which version of Krita?
* What mac do you have?
* What are its specs?
* What's the size of your image, and what is its color model and channel depth?
* How many frames in the animation?
* is canvas acceleration enabled?