[Huawei Y6 Questions & Answers] DuoClip:
Before:

I just unlocked the bootloader and installed a custom ROM (LineageOS 15.1: https://xdaforums.com/huawei-y6/development/lineageos-15-1-huawei-y6-2018-t3832278) on my Huawei but it won't let me flash the TWRP from adb. I tried before flashing the custom ROM and also after but no progress. I tried with 'fastboot flash recovery recovery.img' as well as 'fastboot flash boot recovery.img' because I knew some smartphones include the recovery in the boot.img but I am always getting the same error:

fastboot flash recovery recovery.img
target reported max download size of 535822336 bytes
sending 'recovery' (16544 KB)...
OKAY [ 0.522s]
writing 'recovery'...
FAILED (remote: partition table doesn't exist)
finished. total time: 0.553s

I am not an expert but I understood that 'recovery' partition doesn't exist. I found some possible solutions online such as writing 'fastboot flash RECOVERY recovery.img' or 'fastboot flash erecovery recovery.img' (because Huawei calls the stock one 'erecovery') but they both gave me another error:

fastboot flash RECOVERY recovery.img
target reported max download size of 535822336 bytes
sending 'RECOVERY' (16544 KB)...
OKAY [ 0.522s]
writing 'RECOVERY'...
FAILED (remote: Command not allowed)
finished. total time: 0.528s

UPDATE: I found, maybe, the correct name of the recovery partition and it seems to work:

fastboot flash recovery_ramdisk twrp.img
< waiting for device >
target reported max download size of 535822336 bytes
sending 'recovery_ramdisk' (14026 KB)...
OKAY [ 0.443s]
writing 'recovery_ramdisk'...
OKAY [ 0.323s]
finished. total time: 0.767s

BUT it actually doesn't work properly because when I boot into recovery it boots the stock one. I tried other solutions found on the net like instantly unplug the phone after the flash and reboot it into recovery immediately but again it boots into stock one...

OTHER UPDATE: I managed to find and flash a TWRP that can boot up but it shows the internal storage 0MB not allowing me to install any .zip file. Because of that, I cannot install SuperSU to get root access.

I tried installing TWRP also with stock ROM but still showing 0MB because the phone is encrypted. To disable encryption I need to install the bluspark TWRP (As I found online), the problem is that bluspark won't boot and gets immediately overwritten by the stock ROM as it happened with the one I mentioned in the first update of the post.

Now I will try buying a microSD card and see if it shows right so that I can still flash .zip from the microSD card.

Now:

LATEST UPDATE: The SD card is working properly and I see it as around 60 GB instead of 64 but that's not the problem. I can see the .zip files I'd want to flash but when I try to do it it says me that it failed to mount every single partition and after some research I discovered that my Huawei has all the data encrypted. After other research I found that there are some TWRPs like blu_spark that could decrypt the data but every version I tried doesn't work and gets immediately overwritten by the stock recovery.

Does anyone know other methods to decrypt all the data on Huawei? Otherwise it's impossible to flash any .zip. Actually it flashes it but it fails to update the partitions state so the system doesn't recognize the changes.

Rooting Huawei is so difficult.. I will buy an OP5t as soon as I have the money XD.