[Xiaomi Poco F3 / Xiaomi Mi 11X / Redmi K40] AKASHPAUL:
Installation guide for Arrow OS(Sept 25 build ) + TWRP(3.5.2-alioth-Nebrassy)+ Magisk(23.0) + Viper4android(2.7.2.1 date 28.10.2020) from Stock:-

1. Install adb/fastboot tools from : https://developer.android.com/studio/releases/platform-tools

2. download mi flash unlock tool from : https://miuirom.xiaomi.com/rom/u1106245679/5.5.224.24/miflash_unlock-en-5.5.224.24.zip

3. Sign into MI accont.

4. Switch off the phone and press volume down+power button until it shows "FASTBOOT".

5. Go to platform-tools (in adb/fastboot install directory) . ****+right click and open terminal . run "fastboot devices" . if it shows the device then continue. if not then download fastboot drivers from : https://www.qasimtricks.com/2021/03/download-fastboot-fix-driver.html# . download and unsubscribe the channel(not my channel). Open device manager and install the fastboot drivers.

6. Run the mi flash unlock tool (named as batch_unlock.exe) in "run as administrator" mode.

7. If the device is shown then it will be shown as locked. unlock it . (it will show to activate after 7 days). Wait for it .

8. After 7 days unlock the device by the same method shown .

9. then follow the guide shown above to install arrow OS.

10. Flash Gapps if needed : https://opengapps.org . I feel Nano is good

11. Download twrp : https://androidfilehost.com/?fid=14943124697586373932 . Extract .img fie into platform tools and rename it twrp.img.

12. Go to fastboot mode as shown above then run cmd there (check for fastboot devices) and type: fastboot boot twrp.img

13. go to Advanced > Flash Current TWRP then reboot.

14. Download python : https://www.python.org/ftp/python/3.9.7/python-3.9.7-amd64.exe

15. Download payload dumper : https://mega.nz/file/M0ZVkaDC#-vt_YuqZmi9DFgDTFAuOQxfISU5d-Ui7gxzwEC6uYtQ

16. Extract the payload dumper files in python install directory. Extract payload.bin from Custom Rom zip to the python install directory.

17. run python and enter the following command : "python -m pip install -r requirements.txt" hit enter then "python payload_dumper.py payload.bin"

18. copy the boot.img file from output folder in the python install directory and paste in the phone's storage.

19. download and install magisk from : https://github.com/topjohnwu/Magisk/releases/download/v23.0/Magisk-v23.0.apk

20. tap 1st install button , select and patch a file option ---> boot.img file .

21. copy the patched file found in downloads and paste it in platform tools.

22. go into fastboot and run cmd in pc and run this command : fastboot flash boot <filename.img> reboot

23.

24.open magisk download and flash Audio Modification Library from modules section

25.install Viper apk from ( https://t.me/ViPER4AndroidFXchannel/71 )

open it and grant root permission it will reboot automatically

26.after reboot open magisk and remove Audio Modification Library from modules section and reboot system

27.after reboot open magisk and reflash Audio Modification Library from modules section

28.reboot again

29.open viper enable legacy mode from settings

and you are done. feel free to ask me questions.. I did all the steps and it's working fine . the steps are copied from various sources.