Hi admin,

It would be perfect if there were custom button mapping/configuration.

Here the issue:

I have a problem with camera hard button that doesn't open the camera app after I installed another camera app. Nothing happen after pressing the button in locked screen position, and when you unlock the phone a flash of dialogue will shown up (only for a flash LoL) for us to select the right camera app as the default one (just one or always dialogue pop up). I cant select at all because it disappear right away.

Any idea how to set the default camera app to be bind with the hardware camera button?

you could try Button Remapper, otherwise you'll need to remove the app that caused the issue in the first place, that is if that app doesnt have a button configuration setting in it.
https://play.google.com/store/apps/details?id=com.irishin.buttonsremapper&hl=en

In the app settings menu you can select standard apps. If you select your new camera app there as standard for camera, the button will work with it. If you select no standard camera app the button will ask which one to open.

Okay thanks for the share guys