So after I downloaded Krita and open the app, it'll later just a blank and automaticly close the app. Please fix this

It will be very hard to discover what is wrong without a lot more information. Because, of course, this is not something that happens for everyone, otherwise nobody could use Krita.

At a guess, but it's just a guess, this sounds a bit like https://docs.krita.org/en/KritaFAQ.html ... n-start-up -- which is a problem that occurs when the Windows display/GPU drivers do not provide a recent enough version of OpenGL or Direct3D.

If you're on Windows, please append the output of the Display tab of the Windows dxdiag tool to this thread.

In any case, tell us exactly which OS, which version of the OS, which version of Krita you're using, the brand and model of your hardware.