Mine just works out of the box. You can try reinstall the ROM since you have installed the wrong anx version before so maybe it casue the problem.
Can't enable unknown sources to install apps from chrome
NezukoOS for Redmi 9
What is this?
NezukoOS is a fresh new ROM aiming to provide you a customisable and stable experience!
Unlike others, we actually care about what our users think and are built upon decisions made by our future and current users!
Indicator of apps SOT in battery section.
Bootanimation gets stuck on first boot
Force reboot to fix.
All Pixel Goodies!
Free unlimited google photos storage because we enforce Redfin FP.
Theming of every kind
Power Menu customisations
Battery saving features
Quick Settings customisations
Hardware keys customisations
Power & Volume button customisations
And much more!
ROM Support Group
Device Support Group
Flash a module called MagiskHide Props Config, It should be in magisk app.
then type it again to reboot your device and make changes take effect.