I have been using Krita since 2018. it's the best digital illustration software for me. But since then I am not able use the pen pressure facility in krita. It's frustrating...
I am not using any branded drawing tablet like wacom or huion. I am using a drawing tablet of i-ball WL8055.
if any how this can be fixed. I would be really blessed.

If the tablet has proper drivers for the OS you're using, it should work out of the box. If you're on Windows, you could try to switch between wintab and windows ink in Krita's settings and see whether that helps.