How to install Modded Stock Camera APK without Root?

[HwGeek]

Hi, need some help modding stock camera on Android 9 device, I have modded the stock camera app with APK EasyTool and its signed and all but I cannot Install it, is there some trick without Root to install the modded stock Camera APK? if not as system app - maybe just as a regular App? I wanted to disable the Velvet Denoise option because it takes too much details from the image.
Device: Xiaomi A2 Lite.

 

[Regeneration]

Go to settings > security, check the box of "Unknown sources", and install the APK.

 

[HwGeek]

Problem is that the app already exists and it's trying to update it.

 

[Regeneration]

Guess you'll have to root it or use 3rd party camera app.