How to downgrade android version 14 to android 13

Look at AP or BL string → e.g., A135FXXU3...
- The number before the “U” = bootloader version.
- U3 = Bootloader v3.
If your phone says U2 or lower, Android 13 firmware with the same bootloader is flashable.
If it says U3 (or higher), downgrade is blocked.
Steps to Downgrade (if bootloader allows)
1. Check your model/CSC
  - Go to Settings > About phone.
  - Note model number (e.g., SM-A546B) and CSC/region.
2. Download firmware
  - Get the Android 13 stock firmware that matches your model + CSC.
  - Must be 4-5 files: AP, BL, CP, CSC, HOME_CSC.
3. Prepare phone
  - Backup data.
  - Boot into Download Mode:
    - Power off → hold Volume Down + Volume Up, plug USB cable.
    - Press Volume Up to continue.
4. Flash with Odin
  - Open Odin on PC.
  - Load files into slots:
    - BL → BL file
    - AP → AP file (takes time)
    - CP → CP file
    - CSC → use CSC_**** for full wipe or HOME_CSC**** to try keeping data (not recommended when downgrading).
  - Click Start.
5. Wait for reboot
  - First boot may take 5–10 mins.

Samsung Galaxy A13