How overlayfs works?

[MrMasterDev]

Please tell me about Magical OverlayfS.
Phone: Samsung Galaxy A73 5G
OS version: Android 14
Shell version: OneUI 6.1.1
Firmware: Un1ca Rom
Root Method: Magisk Delata (Kitsune) 27
I do everything according to the instructions. I change the system settings apk file, the translation is in it, but there are no changes. The translation is as it was. Apk have different signatures. That is, I understand that the apk is not being replaced? What is the problem? The kernel allows you to do this and system in rw, i can replace or delete system files manually, other people on the same os and the same kernel work. But people didn't change the translation, but did something else, and I don't know if they did it on A14 and magisk kitsune like I did, maybe on a lower version of android and another root method.

How I did it:

1. Install any Root method (KSU or Magisk).

2. Install Magical OverlayFS.

3. Go to /data/adb/modules/magisk_overlayfs

4. Edit mode.sh as follows:

• Change OVERLAY_MODE to 1 for default RW

• Add DO_UNMOUNT_KSU=true to the beginning of the file if you use KernelSU

5. Reboot your phone.

6. Open Termux or any other terminal application and enter:

su
cp -f "location of modified file" "location of original file you want to replace"

7. Reboot the phone and it should work.

** Some applications check for unusual mounts, so be sure to change OVERLAY_MODE to 2 afterwards.

[Dev-050]

su cp -f "location of modified file" "location of original file you want to replace"

I didn't understand what refers to the location of the modified file and the original file. Could you tell me which file you're talking about?