He metido los comandos del minituto que me has enviado del punto 5 al 9 y esto es lo que aparece:
C:\Program Files (x86)\Minimal
ADB and Fastboot>
adb devices
List of devices attached
adb server version (31) doesn't match this client (36); killing...
* daemon started successfully *
C:\Program Files (x86)\Minimal
ADB and Fastboot>
adb reboot bootloader
error: no devices/emulators found
C:\Program Files (x86)\Minimal
ADB and Fastboot>
fastboot devices
b499c4920104 fastboot
C:\Program Files (x86)\Minimal
ADB and Fastboot>
fastboot oem unlock
...
FAILED (remote: Token verification failed, reboot the device)
finished. total time: 0.071s
C:\Program Files (x86)\Minimal
ADB and Fastboot>
fastboot oem unlock-go
...
FAILED (remote: Token verification failed, reboot the device)
finished. total time: 0.061s
C:\Program Files (x86)\Minimal
ADB and Fastboot>
fastboot oem device-info
...
(bootloader) Device tampered: false
(bootloader) Device unlocked: false
(bootloader) Device critical unlocked: false
(bootloader) Charger screen enabled: false
(bootloader) Display panel:
OKAY [ 0.078s]
finished. total time: 0.078s
C:\Program Files (x86)\Minimal
ADB and Fastboot>
fastboot flash recovery twrp.img
target reported max download size of 536870912 bytes
sending '
recovery' (17774 KB)...
OKAY [ 0.609s]
writing 'recovery'...
FAILED (remote: Partition flashing is not allowed)
finished. total time: 0.641s
C:\Program Files (x86)\Minimal
ADB and Fastboot>
fastboot boot twrp.img
downloading 'boot.img'...
OKAY [ 0.672s]
booting...
FAILED (remote: unlock device to use this command)
finished. total time: 0.703s