- The first thing you need to do is unlock the bootloader.
The problem is that you have purchased the Chinese version.
You can't do anything without an unlocked bootloader.
- Instructions on how to install xiaomi.eu ROM...
How to install xiaomi.eu ROM: https://xiaomi.eu/community/threads/how-to-install-xiaomi-eu-rom-for-devices-a-b.62738/post-624043
How to Install Stock ROM: https://xiaomi.eu/community/threads/how-to-install-stock-rom.74017/post-734380
If you wrote the correct ROM name then it is not official xiaomi.eu ROM.
Here is the official xiaomi.eu ROM:
xiaomi.eu_GARNET_OS1.0.13.0.UNRCNXM_14.zip
If you are not a citizen/resident of Mainland China, you cannot unlock the China Device.
Your only option to unlock the bootloader is to look for a paid service.
If you bought the device as a new piece and you personally did not unlock the bootloader and install the ROM from this forum, you have an official ROM.
Here is the link to the Xiaomi site: https://new.c.mi.com/global/
It looks like you are using an official ROM (SW). You also have no idea what you're doing.
If you have an official ROM and a locked bootloader, this forum is not for you. This signal processing only affects custom ROMs from xiaomi.eu.
It means you don't need a computer to install the patch.
In case you already have TWRP installed on your device.
Do you use a custom ROM from xiaomi.eu at all?